Abstract

Ratawi Limestone in the study area was dposited under transgression and high stand occurences within protected mud dominated condition.The prograding and retrograding (back stepping) geometries controlled the reservoir distribution and entrapment as well as the late digenetic process. The depositional model of the area was constructed using the integrated approach and calibrated with the analogue from cuba. The lateral patchy distribution of the reservoir, that developed by the nature of depositional setting was also reflected at the reservoir quality scale. This was captured from core to seismic scale and feed into the static model to delineate the stratigraphic sweets in the study area for further exploration and development activities . © EAGE Reservoir Geoscience Conference, ResGeo 2018. All rights reserved.

Abstract

The characterization of the clastic Zubair reservoir is challenging because of the high lamination and the oil properties change making the conventional saturation technique uncertain. A new workflow has been recently established in the newly appraised wells which has involved advanced petrophysical measurements along with the fluid sampling. The new technique has led to identify new HC layers that were overlooked by the previous techniques, thus adding more reserves to the KOC asset. Because of the high lamination of clastic Zubair formation and the change of the oil properties, the dielectric dispersion measurement was integrated along with the diffusion-based NMR to identify new oil zones that has been initially masked by the resistivity-based approach. The new approach has also provided details on the oil movability and the characterization of its property. As the newly identified layers were identified for the 1st time across the field, the fluid sampling was conducted to confirm

Abstract

The Greater Burgan Field of Kuwait has been producing for 57 years. The massive sandstone reservoirs have contributed the bulk of oil production. Large reserves are situated in interbedded sandstone reservoirs and will play a critical role in future Greater Burgan development. The current challenge is how to develop these reservoirs that have high uncertainty in net pay. In the recent past, several wells were completed in the interbedded sandstone sequences and no flow was reported. As a result, a review of log, core, fluid, well tests, PLT, pressure data, and the method of net pay determination has been done. The team's objective has been to develop an integrated understanding of the net pay intervals that can contribute to flow at a given API, viscosity, depth, and reservoir pressure. It is assumed that artificial lift may be available, and that drilling, workover, and completion practices do not result in any permeability or perforation damage. A conceptual model has been set up to

Abstract

The unique Kimmeridgian-Oxfordian complex of unconventional and fractured carbonates has been tested to be prolific producer of gas, condensate and light oil in different wells discovered in various North Kuwait fields. The challenge is to characterize the complex reservoir flow system where critical reservoir parameters such as reservoir type, porosity and permeability characteristics, and production and pressure data can vary substantially. The relationship between the natural fractures and the tight matrix in controlling effective system conductivity in reservoir flow units are the key features which dictate the nature of inflow mechanisms thus the production performance. The paper deals with developing an effective methodology which integrates the variations in critical reservoir properties of the low porosity yet naturally-fractured carbonate reservoir. The drill stem test (DST) results in some wells were successful without stimulation, while in other wells the DSTs were unsuccess

Abstract

Instrumentation of artificially lifted wells located North, South-East and West of Kuwait was an essential requirement for real time surveillance of well behavior, and for successful implementation of a digital oil field. The manuscript focuses on challenges and solutions accompanied with setup of a SCADA intelligent software suite and replication configurations applied to remotely monitor and control assets for production optimization purposes. Meetings have been held with Information Technology, SCADA and Well-Surveillance teams to agree on the technical requirements (server's specifications, network diagrams, well connectivity, data road map, data backup, security measures, disaster backup plan, etc...) The availability of having remote terminal unit built-in in the variable speed drive allowed instant access of real time data with ability to remotely control and modify running parameters for artificially lifted wells. Infrastructure has been built based on the company's standard IT

Abstract

Integrated field development studies were performed to increase oil recovery from the Marrat reservoir in the Umm Gudair field, a large, low permeability, complex, naturally fractured and highly faulted carbonate reservoir. The studies involved rebuilding the static model, creating and history matching a new dynamic model and using it to examine redevelopment scenarios. These included well interventions and workovers under primary depletion, secondary waterflood and, following a screening exercise, low salinity flooding (LSF). A new structural interpretation of 3D seismic data provided a revised static geological model and yielded insight into the number, geometry and origin of the many faults intersecting the reservoir. Rock types defined from core analysis were distributed in the static geological model using trends from Bayesian lithofacies classification based on pre-stack inversion of seismic data. Porosity and permeability were modelled by rock type. Saturation-height functions f

Abstract

The North Kuwait Carbonate (NKJG) reservoirs are currently under development by KOC (Kuwait Oil Company). The appraisal and development of the NKJG offer challenges such as lateral variations in reservoir quality, tight to very tight reservoirs and natural fracturing to a varying degree spatially. The presence of open, connected fractures is one of the key elements to achieve a successful development. Also, the presence of fracture corridors increase the risk associated with drilling. Numerous fracture modelling studies have been supporting both appraisal and development strategies of the fields. A structural evolution model has been developed based on field observations and linked to the regional phases of deformations. Detailed fracture characterization using static BHI (bore hole images) and core data as well as dynamic data has been achieved. Small scale detailed DFN (Discrete Fracture Network) in support of planning and drilling activities of future appraisal wells has been carrie

Abstract

Seismic attribute data linked to main fault families interpreted from seismic and structural geology understanding has been used to constrain full field Discrete Fracture Network (DFN) Models. Pressure transient analysis data have also been used to further constrain the DFN models. The seismic attributes have also been combined with horizon curvature to create notional fracture sweet spot maps currently used to support well placement. The DFN models are now being used as input to production history matching and forecast generation. © 2017 SEG.

Abstract

Mauddud Formation is a major oil-producing reservoir in Raudhatain Field of North Kuwait. The Mauddud Formation is an early Albian in age and it was generated an environment of the shallow-water carbonate and consists of Grainstones, Wackestones and Mudstones deposited in ramp settings. In Raudhatain field (RAMA) is undertaking massive development efforts with planned enhancement in Oil production. Reservoir description and distribution of rock properties in 3D space are challenging due to inherent reservoir heterogeneity, in this case primarily driven by depositional and diagenetic patterns. KOC North Kuwait Reservoir Studies Team (NK RST) has been challenged to increase the production from several key NK oil fields. To achieve this goal, KOC has partnered with Schlumberger to rebuild integrated model with Petrophysics, Geophysics, and Geology and Reservoir data of the Mauddud Reservoir. The original model was required to minimize challenges in new infill locations, increase Oil recov

Abstract

Hydrocarbon gas flooding is one of the most applied miscible EOR processes in the oil industry. The process becomes extremely challenging in heterogeneous carbonate reservoirs. An inverted four-spot hydrocarbon (HC) gas injection pilot has been under execution since 2016 to address these challenges, in a heterogeneous multi-layered Oolitic carbonate reservoir in West Kuwait. The pilot consisted of a pre-flush phase of water injection (2016-19) followed by a gas injection phase (2021-2022). This paper describes modelling and history matching of pre-flush waterflood phase and forecasting ahead of gas injection phase. The pre-flush waterflood was carried out sequentially into four target layers, injecting a range of pore volumes in each layer and gathering wealth of pilot data including Inter-Well Tracer Test (IWTT), PLT/ILT, time-lapse saturation logging, coring, and VIT to assess the impact of heterogeneity on the displacement process. Integrated review of the acquired dataset was condu

Abstract

The Kuwait Oil Company's (KOC) has significantly increased its dependence on Artificial Lift systems (AL) to reach their yearly production targets. Multiple AL systems are deployed however the major AL system used is the Electrical Submersible Pump where currently there are over 3,300 ESPs accounting for about 70% of the company's production. Initial implementation of ESPs at the company started in the 1980s, throughout the next few decades only a handful of ESPs were installed. In 2008, ESP installations increased rapidly and currently these ESPs are producing most of the oil production within the company. Over the past 5 years, the ESP population has doubled with additional installations each month. Forecast shows that the ESP population would surpass 4,000 ESPs in 2024. The company's ESP operations is divided into four main assets, North Kuwait, South Kuwait, East Kuwait, and West Kuwait. Each asset has their own staff that monitor the wells under their scope and aim to maximize pro

Abstract

A heavy oil field in Northern part of Kuwait has developed which requires appropriate disposal of produced formation water. Some important questions for water disposal well planning include: • Where to inject? • Where to inject? • What is the maximum operation pressure (MOP)? • How far away the disposal wells should be spaced? • How much water can be inject in each well? Integrated subsurface evaluation performed to address above questions. Seismic data provide a good overview lof the structuration and imporatant insight where sweet spots for injection may be found. Wireline logs and core information are used to derive petrophysical properties, characterize fracture, and gather geomechanical information. Injectivity tests established the injection rate and confirmed the estimated minimum horizontal stress. Analogue water injection data from nearby fields are used to provide information on the dynamic behavior of the reservoir, to reduce uncertainties owing to the limited injection rate

Abstract

This paper demonstrates the production optimization methodology being used by Kuwait Oil Company Jurassic gas that added significant contribution of approximately 37% of total field incremental production gain in 2021. Production optimization is a continuous iterative process to improve production, especially in mature fields. The North Kuwait Jurassic Gas field's team has adopted an integrated enhanced and structured process to identify opportunities for production optimization with a pro-active approach focusing on flowing wells and rig-less interventions to tackle production challenges and achieve production targets. The Jurassic gas asset has unique mature-field challenges. It produces mainly from deep (up to 19,000 ft MD) high pressure and temperature, conventional and unconventional tight carbonate reservoirs, highly deviated to horizontal wells, different completion configurations (4.5in monobore, 3.5in × 5in liner, and 4.5in Multi-stages completions), wellbore cleaning and acce

Abstract

Management of oil and gas resources and reserves has always been complex process as the company’s portfolio consists of resource and reserves volumes with varying degrees of uncertainty and maturity levels of projects. Some of the hydrocarbon volumes are from resources that are highly uncertain and require technology imprevoments or breakthroughs. However, for strategy formulation of the country/company needs consideration of all hydrocarbon volumes that can generate value in the future. The prioritization of development strategies for its reservoirs based on rigorous technical and economic assessments while protecting the national interests is a challenging task. Kuwait Oil Company (KOC) has been using multiple systems for both asset and business planning processes that is not optimized for faster turnaround. The proposed integrated and automated reserves management solution provided a structured environment for systematic economic evaluation and portfolio optimization. It facilitates

Abstract

An unconsolidated clastic reservoir of Middle Miocene age is under full field development plan in the State of Kuwait. Underlying the shale cap rock, main hydrocarbon bearing reservoir consists of two sand bodies separated by predominantly shale interval present throughout the field. To determine the role of facies and depositional environment in controlling the orientation and quality of the reservoir, an integrated analysis of borehole images, open hole logs and core data from wells spread across the field was successfully attempted. Fifteen identified generic image facies principally based on lithology and reservoir quality with core data validation were grouped into six genetically related associations. Facies recognition used criteria of image textural variations, dip patterns, direct recognition of features and relationships of cementation, bioturbation and sediment deformation. Statistical analysis of the identified sandy facies of upper reservoir unit indicated high abundance r

Abstract

Organic-rich Kerogen of Lower Kimmeridgian to Upper Oxfordian age comprises of thinly laminated Kerogen with calcareous mudstone deposited in deep basinal environment. It has a consistent thickness of 50' in the entire study area with an average porosity of 4-6pu with nanodarcy permeability and is the main source for hydrocarbon plays in Kuwait. This rock sequence occurs at depths of 14000-15000 ft under HPHT conditions. Huge success of shale gas plays in North America has prompted the characterization of these source rocks to evaluate their resource play potential for the first time in Kuwait. The Kerogen under study differs from proven US Shale gas fields in terms of comparatively higher TOC content, greater depth and much less in thickness (50ft) and in a Pre-salt setting. Hence these are challenging in terms of completion and production. These are inferred to be Type II Oil & Gas prone based on Vitrinite reflectance range from 0.98 to 1.17. Tight rock analysis (TRA) and geo-mechani

Abstract

Heterogeneous lithofacies distribution resulting into a complex rock-type model in shallow unconsolidated reservoir has a direct role on fluid distribution and trapping mechanisms. A systematic evaluation of these rock-types is necessary for proper reservoir characterization and modeling. In reality, the lithofacies leading to rock-types act as the building blocks to construct a realistic static model, which serves in the understanding of the dynamic behavior of the reservoir. During this study, 202 wells were selected across the field to capture the vertical and lateral heterogeneity of the reservoir, out of which 93 wells have cores. During a first step, a lithofacies prediction model was created from the core sedimentological description, X-Ray Diffraction (XRD), and wireline logs (raw and mineralogical logs) using probabilistic classification schemes. In a second step, petrophysical data like Routine Core Analysis (RCAL), Mercury Injection Capillary Pressure (MICP), were included t

Abstract

Exploration for Hydrocarbon accumulations in Tertiary Rus, Radhuma formations have not been given serious attention until recently in the State of Kuwait. After the successful discovery and production of hydrocarbons from the shallow reservoirs of Lower Fars in North Kuwait, the focus shifted into exploration of other shallow Tertiary reservoirs in Kuwait. The hydrocarbon shows encountered in Rus, Radhuma sections during the drilling of deeper Cretaceous wells in Burgan and Magwa areas and the production from these reservoirs in the neighboring Wafra field made these shallow reservoirs in Greater Burgan area a potential target for exploration. A detailed analysis of the mapped structure with the hydrocarbon indications both on and off the structures observed in the mud logs of wells in the area indicates that the present day structural configuration does not fully explain these hydrocarbon accumulations and the play appears to be primarily strati-structural in nature. Keeping this in m

Abstract

Exploration for Hydrocarbon accumulations in Tertiary Rus, Radhuma formations have not been given serious attention until recently in the State of Kuwait. After the successful discovery and production of hydrocarbons from the shallow reservoirs of Lower Fars in North Kuwait, the focus shifted into exploration of other shallow Tertiary reservoirs in Kuwait. The hydrocarbon shows encountered in Rus, Radhuma sections during the drilling of deeper Cretaceous wells in Burgan and Magwa areas and the production from these reservoirs in the neighboring Wafra field made these shallow reservoirs in Greater Burgan area a potential target for exploration. A detailed analysis of the mapped structure with the hydrocarbon indications both on and off the structures observed in the mud logs of wells in the area indicates that the present day structural configuration does not fully explain these hydrocarbon accumulations and the play appears to be primarily strati-structural in nature. Keeping this in m

Abstract

Exploration for Hydrocarbon accumulations in Upper Cretaceous Hartha and Sadi formations has not been given serious attention till recently in the State of Kuwait. The hydrocarbon shows encountered in Hartha section during the drilling of a Jurassic well in South Burgan area changed this perception and conscious efforts are made to explore the potential of this new Hartha play in the area. A detailed analysis of the mapped structure with the oil/gas indications both on and offthe structure from the mud logs clearly show that, present day structural configuration has a limited role in these hydrocarbon accumulations and the play appear to be primarily strati-structural in nature. Windowed amplitude attribute maps generated from Hartha Formation clearly brought some predominately NE-SW trending long linear anomalous amplitude bodies which are coinciding with the hydrocarbon indications. To further validate these stratigraphic features in Hartha and to better understand reservoir facies d

Abstract

Black Powder has identified as a significant problem in all areas of hydrocarbon production facilities and transit or export lines. The phrase 'Black Powder' in the oil industry used to describe a contaminant found from wellhead, Gathering Centers and gas export lines. The constituents of black powder are known to adversely affect the efficiency, integrity and reliability of oil and gas production, refining and transportation. Its combines of corrosion material such as Iron sulfide, Iron oxide, Wax, Asphaltene, silt and sands. Its vary from one location to another within the process of the oil and gas production. Its presence in all areas of upstream, midstream and downstream oil and gas production. It's affecting the flow assurance and quality of performance of the facilities from compressors, vessels, tanks, sensors and pipelines and finally impacting the refinery efficiency. Its major problem start to be present recently in oil industry which many different operators have different

Abstract

This work comes in the context of a renewed interest in the exploration of deep Jurassic carbonate targets along the Arabian Plate and more specifically in Kuwait. Previous regional and local studies conducted on the Lower Jurassic Marrat Formation focused mainly on structural traps, however a need to tackle complex carbonate systems is required at a stratigraphic level in order to better identify and map subtle trapping mechanisms onshore and offshore. Throughout this new study, a regional geological and geophysical integrated approach was applied in order to complete the sequence stratigraphic assessment of the Marrat Formation, and to identify the architectural evolution of this potential carbonate reservoir including stratigraphic traps deposited on this wide carbonate ramp. A four-step workflow was applied and comprises 1) detailed tectonostratigraphic review, 2) 2D/3D seismic interpretation and 3D seismic characterization, 3) sequence stratigraphic and environmental interpretatio

Abstract

This work comes in the context of a renewed interest in the exploration of deep Jurassic carbonate targets along the Arabian Plate and more specifically in Kuwait. Previous regional and local studies conducted on the Lower Jurassic Marrat Formation focused mainly on structural traps, however a need to tackle complex carbonate systems is required at a stratigraphic level in order to better identify and map subtle trapping mechanisms onshore and offshore. Throughout this new study, a regional geological and geophysical integrated approach was applied in order to complete the sequence stratigraphic assessment of the Marrat Formation, and to identify the architectural evolution of this potential carbonate reservoir including stratigraphic traps deposited on this wide carbonate ramp. A four-step workflow was applied and comprises 1) detailed tectonostratigraphic review, 2) 2D/3D seismic interpretation and 3D seismic characterization, 3) sequence stratigraphic and environmental interpretatio

Abstract

Focused well reviews were carried out to identify productivity enhancement opportunities in a heavy oil reservoir in Northern Kuwait. In an integrated effort, involving multi-disciplinary and cross-functional teamwork, well and reservoir management opportunities were assessed. The goal was to recommend well restoration and optimization opportunities for short, medium and long-term implementation, thereby creating a business impact. The process involved an in-depth comprehensive review of 59 wells. Available completion, production and pressure build-up data were tuned to analytical well models to assess individual well. Inflow performance analyses and the sensitivity check were done for drainage volume. Based on the difference between actual well performance and its estimated potential, production enhancement opportunities for the under-performing wells were estimated with proper engineering judgement. Initial Productivity Indices (PI) were found to be consistently higher than actual we

Abstract

In this study, model based inversion and band limited inversion technique have been utilized for inverting a 3D seismic data set into acoustic impedance volumes from Kra Al Maru area in southwest of Kuwait. Inverted results of study area show that the generated acoustic impedance enhances vertical resolution, which simplifies lithologic and stratigraphic definitions. Both band limited inversion and model based inversion provide strong impedance contrast, probably identifying the thin carbonates within the evaporites. However, model based inversion provides better resolution compared to band limited inversion in identifying lithologies. Significant benefits gained from applying this methodology included improved resolution and delineation of reservoir internal architecture in the Gotnia Anhydrites and in more accurate estimation of reservoir quality and net pay thickness in the reservoir. Despite the recent advent of sophisticated prestack inversion algorithms, poststack model based imp

Abstract

Objectives/Scope: This study focusses on the Wara Formation reservoir in the Greater Burgan Field. The study rapidly assessed the sedimentological and stratigraphic controls on production and water-flood behaviour in the southwest portion of the Wara reservoir in the Burgan Field, which is in the early stages of water-flood development. Methods, Procedures, Process: This eight-week long study delivered a refreshed Wara reservoir zonation scheme in the southwest portion of the Burgan field and new Reservoir Depositional Element Maps. Integration of production data (datum pressures. PLT's-ILT's and tracers), geological data (core, welllogs, analogues) enabled the identification of flow units bounded by significant 'flooding surface shales'. It also showed that communication between these flow units is highly baffled because of the extensive bounding mudstone layers and complex internal flow unit sand and shale body architecture. Results, Observations, Conclusions: Two main Reservoir Mana

Abstract

The study focuses on the stratigraphy and depositional framework of the Wara reservoir. In particular it illustrates how production-related decisions can be guided by both i) an appropriate reservoir layering scheme and ii) population of reservoir layers with depositional elements guided by analogue data. The reservoir layering scheme identifies three reservoir flow units, bound by laterally extensive mudstones, which may be correlated across the Early Wara Pressure Maintainance Project area: -A Lower Wara Formation flow unit comprising multi-storey fluvial/tide-influenced deposits. -Two Middle Wara Formation flow units comprising a complex assemblage of channelised and more sheet-like sand bodies. Production data from the study area indicates that communication between these flow units is highly baffled as a result of the extensive bounding mudstone layers. This has implications for zonal perforation strategies and injector-producer conformance.

Abstract

The Greater Burgan field in South-East Kuwait is the world's largest sandstone oilfield and the second-largest conventional oilfield. The Wara reservoir, in the Greater Burgan field, is a prolific sandstone oil-producing formation. Peripheral water injection into the Wara reservoir is in progress for pressure maintenance and to improve oil recovery from the flank areas. Polymer injection has also been identified as a practical EOR method that can potentially increase oil production and recovery from the Wara reservoir. In view of that and, as a follow-up to a previous Long-Term Polymer Injectivity Test (LTPIT) (Murayri et al. 2022), a second LTPIT was carried out targeting a different area within the Wara reservoir. This paper describes elements of the polymer injection predictions approach, results obtained from a dynamic simulation sector model, before and after polymer injection, in pursuit of phased commercial polymer-flooding development using fit-for-purpose modularized water tre

Abstract

Well placement in an Unconventional Jurassic Formations of North Kuwait is challenged by poor seismic resolution and high uncertainty in the stratigraphy leading to lateral variability of petrophysical parameters and thickness of the pay zone. The 6-9 feet thick target zone is located at 14,000 feet depth with expected uncertainty in the bed dipping angle. Key technologies were deployed to increase gas production in the tight carbonate formation with depositional uncertainties. A pre-well model was built from existing offset wells to assess the well-placement capabilities. A combination of ultra-deep azimuthal resistivity mapping (UDAR) and gamma ray imaging tools were deployed for accurate landing and steering of the lateral section. The objectives were to keep the well trajectory in the payzone, anticipate and identify any abnormalities in the formation while passing through sub-seismic faults and enable rapid response to sudden changes in formation dip due to structural changes. The

Abstract

The Middle cretaceous Wara sandstone reservoir in Minagish Field is considered as highly heterogenetic sandstone which implying lateral facies extensive variations, stacked sand bodies with varying petrophysical properties. Several horizontal wells has been successfully drilled in lower part of Wara 6 sand channel, best thicker clean sand channel with very good oil production rate. Recently some wells have shown depleting of oil and increase water production. To develop such a challenging reservoir to maximize the oil production, a new plan has been developed to explore for new opportunities in Wara reservoir. The objective is to target different good stacked sand bodies in different Wara layers by drilling deviated wells. Some of old depleted Minagsih Oolite reservoir wells have shown good opportunities to sidetrack the wells into good Wara sand layers. This paper presents the integration between geostatistical models, well logs, well test results and different seismic elastic propert

Abstract

Accident and incident investigations have become established procedures in the industry. These procedures have been applied with varying degree of success in many cases. The starting point of any investigation is the setting up of a committee, which is responsible for finding out how and why incidents happen. The committee uses a variety of techniques to understand the incident and attempts to reconstruct the event. The techniques include interviews with personnel, review of documentation/records, reports etc. Traditional investigations usually arrive at causes that are related to equipment, personnel or both. However, recently published investigations go beyond the usual conclusions. Concepts like safety culture, organizational structure and employee empowerment figure prominently in these reports which normally do not find place in traditional investigations. Safety is an emergent property of a system and cannot be considered in isolation from the society and business environment in

Abstract

The Sabiriyah Mauddud limestone of North Kuwait is a super giant depletion drive oil reservoir. Massive development efforts are underway, with a planned enhancement in oil production through phased pattern water flood. The Phase1 development addresses the crestal area (50 km2) of the structure, which was the focus for development efforts in the past. The Phase 2 development consists of all remaining peripheral acreage (200 km2), with immense reservoir rock & fluid uncertainties, leading to the identification of reservoir segments for re-appraisal through drilling & testing of new wells. The fluid description had been a challenge for the reservoir, especially in the mid flank and down flank areas with poor rock / fluid quality. The past data on fluid quality had been the average for the whole of the Mauddud unit perforated together. A serious data gap existed with respect to the vertical variation of the reservoir oil quality. Sampling of formation fluids has been historically not possi

Abstract

The biggest clastic reservoir based in Kuwait has been facing evaluation challenges over the thick intervals of highly laminated thin hydrocarbon layers. Conventional wireline tools have a limitation on resolution when it comes to addressing these thin beds. Therefore, the reserves are usually underestimated, and thin pays are often overlooked. This paper presents the integration of a variety of advanced Wireline tools in order to correctly evaluate and compute reserves from these thin pay zones. Acquisition of the triaxial induction tool enabled the study of resistivity anisotropy and the identification of thin pay zones through the distinct reading of the resistivity of the thin sand reservoir. The thin layers have also been further validated using high resolution advanced thin bed analysis from image logs. Advanced spectroscopy and NMR data were used to quantitively define the sand and shale fractions within the thin beds. These measurements were critical to input to improve the res

Abstract

The study involves a complex sandstone reservoir characterized by relatively thin stratified viscous oil-bearing net pays separated by localized shales and baffles in between. Some of the reservoir intricacies include mappable gas cap intervals overlying net pays at places, water-bearing intervals on top of oil, long transitional zones, and lateral as well as vertical variation in oil viscosity and API. Based on the stratigraphy and geological understanding derived from log interpretation of some initially drilled appraisal wells, the reservoir was divided into four oil-bearing layers: Upper-A, Upper-B, Lower-A, and Lower-B. Upper Sands are separated by Upper Shale Baffle and Lower Sands are similarly separated by Lower Shale Baffle; and Middle Shale acts as a regional barrier between Upper and Lower sand units. Initial reservoir description postulated that all the four oil-bearing layers are separate uncormected units, with no vertical communication. Several hundred wells have been dr

Abstract

The acquisition of open hole logging data is not always guaranteed because of difficult drilling environments. In such cases, formation evaluation, and thus completion program, becomes a real challenge. The situation becomes more complex when dealing with unconventional reservoirs with very tight carbonates and organic carbon-rich formations. This paper presents a method to measure the total organic carbon (TOC), which, in this paper, represents the organic carbon in the matrix (kerogen and coal), and to estimate oil saturation in such challenging environment. A suite of wireline tools (GR, Spectralog, Density, Neutron, Nuclear Spectroscopy), was run through 7 5/8" casing to evaluate the formation and to quantify TOC and the oil in the pores. The nuclear spectroscopy tool, which was the master tool, measures the total carbon in the formation. Part of this carbon is attributed to the inorganic matrix (carbonates), another part is attributed to the organic matter in the matrix (kerogen),

Abstract

The acquisition of openhole logging data is not always guaranteed because of difficult drilling environments. In such cases, formation evaluation, and thus the completion program, become a real challenge. The situation becomes more complex when dealing with unconventional reservoirs with very tight carbonates and organic carbon-rich formations. This paper presents a method to measure the total organic carbon (TOC), which, in this paper, represents the organic carbon in the matrix (kerogen and coal), and to estimate oil saturation in such a challenging environment. A suite of wireline tools (gamma ray (GR), Spectralog, density, neutron, nuclear spectroscopy) was run through 7.625-in. casing to evaluate the formation and to quantify TOC and the oil in the pores. The nuclear spectroscopy tool, which was the master tool, measures the total carbon in the formation. Part of this carbon is attributed to the inorganic matrix (carbonates). Another part is attributed to the organic matter in the

Abstract

Is the seal leaking? Does the cap rock strata have full integrity? Is the system in equilibrium over geological time? Are there any natural flow dynamics prevalent even when the reservoirs are virgin? These are few Frequently Asked Questions (FAQs). These FAQs becomes very critical for any geologically complex and structurally challenging deep high pressured and high temperature, unconventional reservoirs. The unconventional tight-fractured carbonates and kerogen resource-play reservoirs of Deep North Kuwait Fields, underlain by anhydrite-salt layers of cap rock, have given rise to similar questions in the early stages of development for successful economic exploitation and field development. Stoneley waveform data can be used to identify fractured interval and estimate open fracture's width in a borehole. The method uses direct and reflected Stoneley wave arrival measured by the full waveform array sonic tool. The Stoneley wave, when passing a fracture which is intersected across a bo

Abstract

This paper describes an efficient assisted history-matching (AHM) workflow that integrates production logging tool (PLT) data, streamline trajectories, and tracer data for fields with high-permeability streaks (thief zones). A field case study from North Kuwait of Sabriyah Mauddud (SAMA), a giant carbonate reservoir with more than 400 producers, is presented to demonstrate the application of the new AHM algorithm. In this field, the presence of thief zones was identified during a waterflooding period when water breakthrough occurred much earlier than expected. Data from the PLT and limited core plugs also supported the presence of thief zones in several layers of the reservoir and confirmed the majority of the water was flowing through these thief zones. Therefore, PLT data-derived thief-zone logs were used to populate the distribution of thief zones in the geomodel. However, reservoir simulation demonstrated that cumulative water production was significantly lower than the observed va

Abstract

The North Kuwait Carbonate (NKJG) reservoirs are currently under development by KOC (Kuwait Oil Company). In addition to the matrix heterogeneity, natural fracturing poses extra challenges for the optimization of the field development planning. The presence of open, connected fractures presents opportunities for infill drilling but increases the risk of water invasion and drilling related issues. Numerous fracture modelling studies have been supporting both appraisal and development strategies of the fields. The translation of the field observation and detailed fracture characterization using static BHI (bore hole image) and core data yields a series of geological concepts. These concepts capture end members of the spatial distribution of the major conductive features and provide a range of realizations for the geometrical extent of the fracture zones. Given the large uncertainty in the dynamic properties of the fracture; pressure transient analysis (PTA), complemented by core data, ha

Abstract

Hydrocarbon production from the Minagish Formation of early Cretaceous Berriasian - Tithonian age in Kuwait is primarily from the West Kuwait fields such as Minagish and Umm Gudair. Exploratory efforts for this play equivalent have not met with much success in other parts of the country. Primary reason for this is lack of trap integrity in the west and unfavorable facies development in the north and north-east. Integration of seismic analysis and geological understanding was applied to decipher the palaeo-basin configuration for this play in western Kuwait. Analysis of seismic attributes, particularly seismic waveform characterization has helped in mapping an edge of the prograding, high energy facies corresponding to the middle unit of the Minagish Formation, which is the main producing unit in the West Kuwait fields. Both 2D and 3D seismic data sets were used for this study. 2D data has provided the general trend of the facies, whereas with the addition of 3D seismic it was possible

Abstract

The Wara sandstone reservoir in the Minagish field of Kuwait Oil Company is a complex deposition of a typical pro-deltaic environment consisting of shaly-silty sandstone sequences W7-W1. Three sequences (W6, W5, and W3) were expected in the case study well. The objective was to set 95/8-in. casing at the top of W6 and then drill through the Wara sequences to connect all of them and land and drill the lateral section within W3. The W6 sequence is typically the primary target in the Wara formation, being thick and consistent throughout the field. The next logical step in developing the Wara reservoir was to study and investigate the minor W5 and W3 members. Due to poor correlation of W5 and W3 channels in offset wells, the geological target was selected based on seismic Poisson impedance. Historically, targeting the Wara formation occasionally resulted in multiple sidetracks due to drilling challenges. A real-time geomechanics service was utilized to overcome drilling challenges and real

Abstract

The Wara sandstone reservoir in the Minagish field of Kuwait Oil Company is a complex deposition of a typical pro-deltaic environment consisting of shaly-silty sandstone sequences, referenced as W7-W1. Three of these sequences (W6, W5, and W3) were expected in the case study well. The objective was to set a 95/8-in. casing at the top of W6 and then drill through the Wara sequences to connect all of them and land and drill the lateral section within W3. The W6 sequence is typically the primary target in the Wara formation, being thick and consistent throughout the field. The next logical step in developing the Wara reservoir was to study and investigate the minor W5 and W3 members. Due to poor correlation of W5 and W3 channels in offset wells, the geological target was selected based on seismic Poisson impedance (PI). Historically, targeting the Wara formation occasionally resulted in multiple sidetracks due to drilling challenges. A real-time geomechanics service was used to overcome d

Abstract

Structural uncertainty is defined by creating stochastic error surfaces built on control points. Uncertainty is zero at the drilled locations and varies smoothly away from the wells. The other factor that enhances uncertainty is fault-zone. This study aimed at generating a composite model integrating these two determinants of structural uncertainty. The study is done on Mauddud surface in part of the Greater Burgan Field, Kuwait. The seismic guided surface was created incorporating tops of 13 drilled wells. Sequential Gaussian Simulation was used to generate stochastic error surfaces having normal distribution using these 13 zero value control points as input. Deviation of the actual Mauddud top from the given seismic surface was calculated to be to the tune of ±60′. The stochastic error surfaces were multiplied with a constant so that the surfaces closely represent the perceived uncertainty captured in these drilled wells. Seismic variance attribute was used to capture the uncertainty

Abstract

Hydrogen damage to pressure vessels in a Crude Oil Production facility is not uncommon. The intriguing question is about the decision to continue affected vessels in safe operation if such decision is supported by an accurate engineering assessment of the damage and the impending risk. Engineering assessments of the vessels instill confidence for safe operation and help in minimizing production loss & capital expenditure. This paper presents the integrity assessment undertaken during the years 2004-2005 for pressure vessels of an upstream oil production facility (Gathering Centre) of Kuwait Oil Company (KOC), where high H2S (hydrogen Sulfide) levels in the process streams have made the pressure vessels susceptible to hydrogen induced damages. These carbon steel pressure vessels were manufactured to ASME Section VIII Div 1 during the years 1961-1968. As part of elaborate Inspection Program of the pressure vessels in the Gathering Centre, ultrasonic testing was conducted on all the hydro

Abstract

Any lapses in design or operating practices predominately in the form of departure from the design intent or standard operating procedures have the potential to lead to undesirable events. The resulting design or operating deficiencies once recognized are usually mitigated by add-on safety features, robust practices, effective training and efficient emergency plans; orelse passively by incident investigations. All of which fall under an Integrity Management System. Effective Integrity Management Systems are assessed through performance indicators that measure accountability and ownership and the mitigating measures effectiveness (individual programs and the management system key elements as a whole). However, even with an effective management system there will always be a dependency on intermediaries and a degree of subjectivity in assessment; therefore there is no replacement for intrinsic safety features and a competent operating workforce. KOC has recognized that integrity managemen

Abstract

The professionals across the Oil & Gas industry have strived to combat the adverse effects of Hydrogen Sulphide and maintain the integrity of vital facilities. The detrimental effects of Hydrogen Sulphide on process equipment has remained as one of the prime subject of research in Oil & Gas Industry, fostering the advancement of inspection philosophies and necessitating adoption of appropriate mitigating measures. The challenge of Integrity Management increases with the ageing of equipment and increased influx of sour media. This paper discusses: • The change in operating environment - from non sour to sour. • The actions taken to protect the equipment in the changed operating environment. • Consequent changes in the inspection strategies and techniques to detect material degradation. • Material protection methodologies deployed to manage the age old facilities for safe operation. This paper gives an insight into the various methodologies adopted in KOC to address asset/plant life exte

Abstract

Global oil demand has led to the development of new smarter drilling, completion, reservoir management technique and technology to optimize reservoirs production. The production of Kuwait Oil Company (KOC) has reached 3 MMBOPD and KOC's 2030 vision is to boost the production to 4 MMBOPD. In order to achieve this vision, KOC has started several technical projects and development plans. One of these projects is the North Kuwait Integrated Digital Oil Field (NK-KwIDF) a full-fledged Field project implemented in KOC. This Paper will discuss the scale, complexity, technology used, and advantage of using the NK-KwIDF. The North Kuwait (NK) asset has five fields, around twelve hundred active wells, and seven Gathering Centers (GCs). A complex network of pipeline, trunk line, and manifold are used to connect these twelve hundred wells to GCs. In order to optimize the production from NK every barrel of production opportunity has to be considered by optimizing suitable wells and minimizing downt

Abstract

During the progressive development of mature fields, it is imperative to drill many infill wells to accelerate production and access bypassed oil. Optimizing the infill well spacing is always the concern to reduce interference with existing wells and improve recovery. In the present study, using intelligent data mining techniques, a new analysis and visualization tool has been developed and implemented to estimate and map drainage radius by well to assess the efficiency of the current development pattern and properly plan future wells. The tool deployed several performance-based techniques to estimate the contacted stock-tank oil initially in place (STOIIP) by each existing well, and outcomes can be compared between techniques for validation. The contacted STOIIP is then converted into an effective drainage radius by well using reservoir properties from the geo-cellular model. The evaluated reservoir is subdivided vertically into pay zones drained by the wells based on geological barri

Abstract

Mutriba is a prominent NNW-SSE trending anticline in Western Kuwait. Hydrocarbon prospectively of the structure is confirmed with multiple pay zones at Triassic, Jurassic and Cretaceous levels. Such levels are well known in the Middle East for being severely contaminated by coherent inter-bed multiple reflection events and the seismic data suffers from poor resolution at deeper levels. These multiples have the same velocities as primaries and cannot be adequately attenuated during processing. As a result, Acoustic Impedance (AI) predicted from such seismic data is significantly affected. We present here a recent study which incorporates an InterBed Multiple Modeling (IBMM) into the generation of synthetic seismograms, which are involved into the seismic inversion workflow. As the observed seismic events are honored, the prediction of the AI model is optimized and less corrupted by the presence of the inter-bed multiples within the target levels. This methodology has been successfully a

Abstract

Removing interbed multiples from seismic data can be vital if the interpretation of those data is to be accurate. Previous experience has demonstrated that this is the case in the area of onshore Kuwait that forms the subject of this case history. VSP and well-log data are used to identify the main generators of the interbed multiples that contaminate the target zones. Interbed multiples corresponding to these generators are then predicted using a data-driven technique, and these multiples are adaptively subtracted from the recorded data. Improvements in both the well ties and the interpretability of the results demonstrate the value of the process. © Society of Exploration Geophysicists - 75th SEG International Exposition and Annual Meeting, SEG 2005. All rights reserved.