Abstract

A Large Scale Thermal Pilot (LSTP) has been in operation in Northern Kuwait in a Heavy Oil Field for some time. Currently, the pilot wells are on Steam flood (SF), after completing two cycles of Cyclic Steam Stimulation (CSS). This paper presents the analysis that led to the improvement of reservoir performance, and the critical learnings from monitoring the steam chamber development from different well completions. The LSTP in the North area of the field consists of 26 vertical production/injection wells, distributed into eight inverted 5-spot patterns. One is a 10-acre area pattern targeting one reservoir unit and the other one is a 5-acre pattern area targeting two commingled reservoir units. A systematic approach for data integration was used by multiple disciplines to improve the thermal recovery of the pilots. This integrated approach led to gaining thermal recovery field experience and learnings for improvement of future commercial development thermal operations in the subject h

Abstract

The paper presents an analytical solution of Buckley-Leverett (BL) equation in gas displacement process including viscous fingering and gravity effects at constant pressure boundary conditions for the inclined stratified heterogeneous reservoir. First, the governing equations related to the change of fluid properties, which govern viscous fingering are discussed. Then the gas flood BL-equation accounting for gravity and miscibility effects for inclined stratified heterogamous reservoir are developed and solved analytically using fractional-flow theory and MOC (method of characteristics). The analytical solution provides the guidance to predict the oil recovery through pressure and saturation distribution at any given time for horizontal, inclined, homogeneous and heterogeneous reservoirs. The results of the analytical solution (total volumetric flux, breakthrough time, front location, saturation and pressure) are compared with finite-difference numerical simulation using CMG simulator.

Abstract

Under the present budgeting system that is in vogue for many years, there is significant uncertainty concerning the Scope of Work (SCOW) at the Budget Proposal stage, giving rise to escalated cost estimates, which in turn lead to excessive carried over expenditure. That process gave rise to rush at the eleventh hour detrimental especially to the functioning of the executing arms (Controlling Groups) within the Company. A number of lacunae have been noticed. No feasibility study indicating the detailed evaluation of various alternatives and their economics was provided. The cost estimates are furnished without any front-end engineering. Sufficient time was not allowed to seek budgetary quotations. More often than not, nearly 50% cushion was provided in the estimated costs. Owing to these shortfalls inherent in the budgeting process, there was too much carried over expenditure with unspent funds (under-expenditure). In an effort to resolve these shortcomings, the Company came forward wit

Abstract

Waterflood oil recovery in many carbonate oil reservoirs is low due to both high residual oil saturations and low sweep efficiency because of high heterogeneity. An example is the Sabriyah Mauddud reservoir in Kuwait. Alkaline-surfactant polymer flooding (ASP) has great potential for enhanced oil recovery both because ASP flooding reduces residual oil saturation and because of the polymer improves sweep efficiency. Unfortunately, the initial ASP coreflood experiments using conventional alkali showed unacceptably high surfactant retention in the reservoir cores. Several approaches to reducing surfactant retention were tested. Numerous strategies such as the use of chelating agents, sacrificial agents and chemical gradients were tested to reduce retention. The most effective strategy used a hybrid-alkali (NaOH + Na2CO3) in addition to a hydrophilic polymer drive containing a novel co-solvent. In this approach injection pH was increased to 12.5, compared to 10.5 using only Na2CO3. Such hi

Abstract

Drilling in North Kuwait presents significant challenges due to the hard rock in the overburden that needs to be drilled in large hole sizes en route to the targeted deep Jurassic reservoirs. A project was taken up in order to improve the drilling performance (especially Rate of Penetration, ROP) thought the hard layers located in three upper sections of the wells (28, 22 and 16) by implementing the Drilling Efficiency Optimization (DEO) methodology. DEO is an overall process to improve drilling performance by increasing ROP and bit footage through the utilization of efficient drilling practices throughout the planning, execution, and post-drilling phases. This paper describes the strategies, practices and Driller Roadmaps that were developed to improve ROP and drilled footage on the three sections of interest. The drilling parameters and results from three trials implementing the proposed improvements are also included. Field data demonstrates that by optimizing BHA (Bottom-Hole Assem

Abstract

Kuwait heavy oil development target reservoir is a shallow, sub-hydrostatic and unconsolidated sandstone with relatively high porosity and permeability. Due to nature of this reservoir, well intervention operations in North Kuwait Heavy Oil Asset exhibit a higher risk of significant fluid loss that causes wellbore impairment, incremental operational costs, excess brine volume usage, and more importantly a significant impact on production deferment. The latter is due to formation damage and the time required to produce the completion fluid that is lost to the reservoir during any well intervention. The objective of using a cost-effective and less non-damaging fluid is achieved by the application of a novel customized salt system that was successfully trialed in the field. A systematic research was employed to find a suitable product/system that could be used in sub-hydrostatic conditions, able to effectively control fluid loss while retaining as near the original permeability. This new

Abstract

A high-resolution reservoir characterization workflow is applied to assess the off-structure prospectivity of Lower Jurassic complex carbonate reservoirs of the Marrat Formation in the southern part of The State of Kuwait along the Dharif-Abduliyah fields. A detailed sedimentological and petrophysical assessment was integrated with 3D seismic interpretation and delineated vertical and lateral facies changes within the fields, which are affected by sets of complex fault patterns. Carbonate geo-bodies have been mapped using seismic stratigraphy, and 3D multi-seismic attribute and seismic acoustic inversion workflows. The Middle Marrat has been subdivided into 5 units (Middle Marrat 1-MM1 to Middle Marrat 5-MM5) that show vertical and lateral lithological and facies variability. The developed integrated sequence stratigraphic framework permitted to better assess the influence of accommodation variations as well as carbonate ecological settings on sedimentary facies development. This frame

Abstract

The DCS (distributed control system) alarm system of gathering center of West Kuwait field at Kuwait Oil Company was not functioning as required. DCS alarm system was generating around 400 to 700 alarms in one hour which was out of operator's alarm handling capacity. This was highlighted as one of the key contributing factor to the seriousness of process upsets & incidents. The overall alarm management system was thoroughly investigated to understand root cause of these poorly functioning system and to improve it accordingly. A detailed investigation revealed lack of alarm management philosophy during design stage and subsequent over configuration of DCS alarms as main cause of this poorly functioning system. All DCS alarms were analyzed in detail to eliminate all unwanted alarms to achieve manageable alarm level of around 5-20 alarms per hour. This paper shares field experience for analysis of DCS alarm system and explains main root causes which resulted in such poorly functioning ala

Abstract

The DCS (distributed control system) alarm system at Gathering Centers of Kuwait Oil Company was not functioning as required. DCS alarm system was generating high no. of alarms which was out of operator's alarm handling capacity. This was highlighted as one of the key contributing factors resulting in process upsets & incidents. A detailed investigation revealed lack of alarm management philosophy during design & operation stage as main cause of this poorly functioning system. This paper shares field experience of analysis of DCS alarm system and explains main root causes which resulted in such poorly functioning alarm system at oil and gas gathering centers. It provides guidelines to carry out alarrm management exercise for improving DCSalarm system & for developing alarm management philosophy to implement and sustain efficient DCS alarm system. It also shares some of the actual alarm data and their analysis, which supports need of well-developed alarm management philosophy and contin

Abstract

During the whole Facility Life Cycle of a Gas handling plant, Risk Management for protection of environment and communities and prevention of major hazards along with Asset Management are the key drivers for making the facility compliant with Health & Safety Regulations and Environmental issues and at the same time profitable economic and able to preserve asset value by improving the level of operational and process safety has become a crucial and challenging issue in a HSE perspective in Gas handling facilities. Process safety can be placed at the intersection of these independent but interrelated aspects and can be regarded as the key element for performing an integrated and comprehensive analysis capable to maximize plant effectiveness ensuring the best safety level, minimizing risks to safety and security and limiting at the same time downtime due to operational disruption or interruption, thus achieving consistency throughout the whole project life cycle. Therefore an effective pr

Abstract

The manuscript focuses on benefits realized in sucker rod pump system performance, number of workovers, downtime periods, and overall production efficiency as a result of continuous steam injection (steam flooding) on a heavy oil pilot field. It also presents benefits on production performance as a result of realtime well optimization of sucker rod pump systems. Implementation of real-time production optimization techniques to record behavioral changes provide for up-close field operational surveillance (allowing for faster response time). The steam injection effect varies from between locations, based on the distance between injector and producer wells, along with the degree of down-hole interference. The objective was to study steam injection effects on a group of wells and adjust the operational parameters of sucker rod pump systems based on individual well performance conditions. Real-time wellsite monitoring (including creating notifications, warnings and alarms to identify troubl

Abstract

The selection of the best EOR option for optimizing the recovery in a field development plan is probably one of the most difficult decisions, as many parameters and options, as well as uncertainties play a role difficult to rank and characterize. This work presents the application of a new methodology, Fuzzy Analytical Hierarchy Process (FAHP), aimed to select the best EOR option, illustrating its practical application to a heavy oil field development case. In order to rank efficiently prospects opportunities and exploitation scenarios the most common approach is the evaluation based on economical parameters. However, technical parameters like well-types options, facilities configurations, transport options, operability, and reliability, are not strictly, nor solely economical parameters, hence, not easily considered during the screening and selection phases of the FEL (Front-End-Loading) process. When the number of options and parameters becomes very large, the human judgement must be

Abstract

Torsional vibrations are a very common phenomenon affecting drilling operations by limiting efficiency, increasing the risk of downhole equipment failure and generating additional costs, particularly when their most severe form is encountered, the stick-slip. It is less known that torsional vibrations also strongly affect directional drilling operations reducing directional stability and tool face control. In this paper, the highly variable solicitation induced by torsional vibrations is addressed with a statistical approach. This approach, used successfully in Kuwait applications, resulted in an operational savings of 30% of the cost per foot over a panel of more than 15 runs analyzed. Steerability and directional stability is critical on directional wells, especially when using push-the-bit systems with PDC bit due to side force distributed unevenly over one bit revolution. Most of today bit design comparisons are made with an average steerability factor computed over one full revolu

Abstract

The evolution of horizontal drilling methodologies and subsequent completion strategies has successfully tackled numerous reservoir access hindrances. As the industry leans towards optimal operational expenditure and the augmentation of reserve extraction via amplified reservoir engagement, there's a growing emphasis on sophisticated multilateral well architectures. Nevertheless, these multilateral configurations pose intrinsic challenges to rig-based interventions, especially those heavily reliant on precise lateral profiling and access. In North Kuwait, an operator executed drilling of a tri-lateral well, aiming for heightened reservoir engagement in both the lower and upper Mauddud carbonate strata. This strategic approach addressed diverse production paradigms while maintaining economic viability. Consequently, this intricate completion necessitated a revolutionary intervention methodology that employed coiled tubing (CT) optical telemetry coupled with a multilateral indexing entry

Abstract

Electrical submersible pumps (ESP's) downtime is one of the most significant concerns that affect the oil production sustainability. Various defects as electrical trips, mechanical issues, under or over load trips and manual shut off are keeping the pumps off operation that would suspend the well productivity. The downtime of ESP's generized by generators globaly is exceeding an average of total 2 days per well from a population of 400 pumps. This is directly reducing the total daily production. The objective is to reduce the operational downtime by 50% after allocating the most marking defects to increase the pump's spinning time and maintain the wells' production. Statistical study using the Six-sigma procedures is employed to accomplish the downtime reduction. The problem is defined as reducing the ESP's downtime by 50%. The spinning hours are measured in daily bases from 400 wells and the downtime is calculated. Moreover, each defect is categorized to a main reason branch. The bran

Abstract

Objective/Scope: The main objective is to find a way to increase the well production and sustain theproduction by connecting the reservoir through several stages of fractures spaced throughout the horizontaldrain hole. Method, Procedures, Process: Exploratory wells targeting Mauddud reservoir were normally drilledvertically and stimulated in a conventional way using matrix acid treatment, which proved a goodhydrocarbon potential, but with low productivity. A study was conducted in one the lower cretaceousreservoir (Mauddud) which recommended the option of drilling a horizontal well in the mentioned reservoirand applying multi-stage acid frac for productivity enhancement and sustainability. The target carbonatereservoir is tight, has a porosity of approximately 12-20% and permeability between 0.05 to 2 md. Thefirst horizontal well for Maudddud reservoir was drilled up to a measured depth of 11,171 ft MD with ahorizontal section of 2,752 ft. It was completed with swell packers and seven

Abstract

In one of the prolific fields in Kuwait, achieving zonal isolation posed a big challenge mainly due to setting the production liner shoe close to the oil-water-contact zone. Cement bond logs from the primary cementing jobs were not acceptable due to contamination from intruding water leading to a high water-cut in the produced oil. We review the first implementation of a self-sealing Cementing System in Kuwait to improve zonal isolation and cutting the water production. A comprehensive pre-job study was executed to engineer a suitable cementing system containing a swellable elastomer for oil-water-cuts with proper test in Lab. A novel HPHT multi-function test cell apparatus and procedure were utilized to measure in-situ ability of fractured cement specimens to seal oil-water-flows under the given simulated downhole conditions. Shrinkage or expansion of the set cement was also verified under pressure and temperature with a continuous test method run over several days. Thorough lab tests

Abstract

The US still the world's dominant crude-oil producer, and although OPEC was able to increase oil prices significantly via nationalization, the US became a net oil importer. The result of the rise in prices is the development of productive capacity in the North Sea, west Africa, and the deeper waters of the Gulf of Mexico was economically justified. Meanwhile, the government and industry strategists were considered alternatives such as oil shale, tar sands, and coal. However, by using these alternatives, it yield another hydrocarbon fuel. Addressing this issue, there are some solutions offered such as to increase the tax on gasoline to dampen demand; tax carbon emissions and institute carbon-off-setting regulations; consider rewarding carbon-dioxide sequestration; and encourage truly green alternatives such as solar, wind, geothermal tidal, and wave sources.

Abstract

Traditionally most Reservoir Engineers give emphasis in matching Water-Cut, GOR, SBHP/FBHP and Cumulative Oil/Water & Gas production. Matching the above said will yield good results at the well level, however what is happening within the layers where the well is completed still remains unclear. In addition to the conventional production data matching various well surveillance data like Pressure from the RFT data will enhance tracking of the Vertical/Aerial distribution of reservoir fluids. Matching PLT data will result in improving the relative contribution of different layers in the dynamic model. Capturing time-lapse changes of Water/Gas saturation as observed from the TDT/PNC logs in the model will mimic fluid flow and saturation changes in the dynamic model closer to reality. Identifying the amount of water unwantedly being injected in to the reservoir due to casing integrity and simulating its effect during history matching will help in capturing its impact on increasing water sat

Abstract

In rod pump applications around the world heavy oil and sand production is believed to be a dangerous combination. This paper highlights a case study of a heavy oil well in the North Kuwait field where sand production was monitored closely to avoid flow line choke and down hole failures. This case study was used as a pilot for the neighboring wells producing from the same reservoir. In case of wells producing heavy oil with considerable sand production and that undergo cyclic steam stimulation the challenge is often at the end of the production cycle. While the oil is thin and has good viscosity the sand settles itself at the bottom. However, with time as the oil gets colder and thereby heavier, it carries the sand along with it to the surface causing plug in the flow line. This is due to the high viscosity of the oil. This is believed to be the end of production period beyond which it would have been impossible to produce any further even after sand cleanup. Certain operational proced

Abstract

Well integrity was and continues to be a significant priority for many operating companies around the world. A compromise in well integrity may have direct impacts on production sustainability well life and the environment. Well integrity became an important topic in the last decade after a number of the well blow-outs and oil spills around the world. The new electromagnetic time domain tool (EM) which is presented uses transient or Pulsed Eddy Current (PEC) measurements to perform quantitative evaluation of downhole corrosion in four concentric tubulars individually and to inspect a fifth tubular qualitatively. Case studies are presented that compare results of this instrument with industry-standard single-string evaluation tools such as multi-finger calipers. The novel electromagnetic tool which uses transient or PEC technology comprises three sensors which achieve high-resolution of the inner barrier and high radial depth of investigation for up to five barriers. Each sensor induces

Abstract

Stimulating source rocks using hydraulic fracturing in unconventional source rocks is a common process. But such practice has not been followed when dealing with tight reservoir rocks. Tight carbonate reservoir rocks have in general been subjected to multistage acid fracturing. This paper describes the analysis of actual performance data to acid fracturing in a tight carbonate formation and the ineffectiveness of the process as measured by the performance responses of the producing wells. The case study relates to a tight formation that is considered a reservoir rather than a source rock. The formation permeability is in the range of 0.1-5 millidarcies. Development has been through numerous horizontal wells with limited multistage acid stimulation. Analysis of performance data for more than 30 wells Indicates no fracture flow and very limited stimulated production. Different diagnostic methods were used to determine the nature of the flow regime and to examine the true benefit of multi

Abstract

[No abstract available]

Abstract

Optimal location of infill wells is very important in the development strategies of any reservoir. It is even one of the most challenging tasks for waterflooding projects in heterogeneous reservoirs. The new infill wells have to be located based on optimum reservoir management practice taking into considerations several reservoir parameters. Usually, there are several potential locations of the new infill wells. Selecting and evaluating of all the possible candidate wells using fine scale models is neither computationally straightforward nor time efficient for geological models consisting of millions of grid cells. This paper presents a practical and cost effective method that minimizes the number of simulation runs and maximizes oil recovery by optimizing infill well location. The proposed method consists of upscaling the geological reservoir model from fine scale into a coarser scale while preserving the important characteristics of the fine scale model. The proposed approach uses wa

Abstract

Purpose: To evaluate the clinical and genetic spectrum of inherited retinal diseases (IRDs) in a Kuwaiti tribe. Methods: Forty four patients with IRDs from 28 nuclear families from the tribe, were evaluated for presenting symptoms, visual acuity, fundus examination, OCT, microperimetry, full-field (ff), and multifocal electroretinography (mERG) and genotyping. Results: Seventeen patients were diagnosed with autosomal recessive retinitis pigmentosa (arRP) associated with RP1 c.606C>A with onset of nictalopia in the third decade, myopia, and macular atrophy by the age of 50; eleven with autosomal recessive cone/rod dystrophy or macular dystrophy associated with RP1 c.606C>A (p.Asp202Glu) mutation with color and central vision deterioration in teenage, myopia, paracentral ring scotoma and macular atrophy; eleven were with arRP associated with PDE6B c.992 + 1 G > A mutation with onset around 5 years, myopia, cataract, retained central fixation, and ellipsoid zone and late perimacular atrop

Abstract

Background: The association between admission pulse pressure (PP) and cardiovascular outcomes in acute coronary syndrome (ACS) is not well defined. Aim: To explore the prognostic value of initial PP in ST-segment elevation myocardial infarction (STEMI) and non-ST elevation ACS (NSTE-ACS). Methods: Over a 5-month period in 2007, 6704 consecutive patients with ACS were categorized into five groups according to initial PP: P1, PP ≤ 0; P2, PP 31-40; P3, PP 41-50; P4, PP 51-60; P5, PP > 60 mmHg. Patient characteristics and in-hospital outcomes were analysed. Results: Mean PP was lower in men versus women (55 ± 19 vs. 61 ± 22), young versus old (53 ± 17 vs. 59 ± 21), STEMI vs. NSTE-ACS (51 ± 18 vs. 60 ± 18) and patients who died versus survived (46 ± 22 vs. 57 ± 19 mmHg) (P < 0.001 for all). Most patients with low PP had a high Global Registry of Acute Coronary Events risk score. Compared with P5, crude odds ratios (ORs) (95% confidence intervals) for death were: P1, 9 (5.78-13.35); P2, 3 (1

Abstract

Reduced land slots availability for drilling of new wells, operator's focus to increase production, aim to reduce effective cost per barrel and to minimize the environmental footprint, worldwide drilling contractors/operators are looking for various solutions available to address these concerns. Drilling multilateral wells is one of the solutions to these concerns. This paper presents the process and steps followed in planning and decision making for drilling a multilateral well in one of the North field in Kuwait, which includes 1. Identification of filed and understanding formation, 2. Categories of multilateral wells and selection of level and types of multilateral well, 3. Pre requisition of data for level 1 multilateral well, 4. Selection of well slot and reviewing additional tools/service requirement, 5. Selection of well trajectories for multilateral well, 6. Selection of open hole junction point, 7. Selection of section TDs, 8. Review of directional BHA & its suitability for op

Abstract

Summary The North Kuwait Jurassic complex (NKJC) consists of six fields with four potential reservoirs in a naturally fractured Jurassic carbonate formation. Current understanding of the complex has led to 12 subdivisions of the area and potentially 48 separate compartments (segments) in the complex. These subdivisions are defined by fault boundaries supported by a combination of variations in fluid composition, initial pressures, and free-water levels estimated from capillary pressure and log saturation data. Multiscenario production forecasts based on integrated fullfield modeling were needed in the process of building a field-development plan (FDP) for the NKJC. An integrated asset modeling (IAM) framework is adopted in which multiple separate reservoir models are coupled through global constraints to meet gas-delivery targets. We present the results of a feasibility study to select the optimal modeling strategy for the complex. We discuss available options to simulate multiple rese

Abstract

Hydrocarbon exploration along the Arabian Peninsula is almost celebrating a century of successes. Major structures were drilled and hundreds of billions of barrels consequently discovered and still producing at increasing rates. Remarkable multi-scale and multi-disciplinary dataset (e.g., 2D, 3D seismic data, core and well log data and imagery⋯) have been acquired in the past decades allowing geoscientists to better assess the diverse onshore and offshore Petroleum Systems' potential. Many challenges linked to the exploration of new hydrocarbon resources in such Mature Basins are driving innovative ideas towards the identification, the assessment and the de-risking of new subtle Plays. "Integration" remains a key problematic that needs to be tackled in order to answer properly to how much resources are still left unexplored. Thus, multi-disciplinary expertise, multi-scale dataset combination should be supported by recent technological advances in data acquisition and processing (e.g.,

Abstract

The productivity of wells drilled into naturally fractured reservoirs is often unpredictable due to the highly heterogeneous nature of the reservoir. In such reservoirs, productivity is a function of complex processes involving the density and aperture of fractures, their interconnectivity and the quality of the surrounding rock matrix. For reducing the risks associated with drilling of new wells for field development, one approach consists in creating multiple equiprobable reservoir models constrained to both static and dynamic data. We further propose to associate with each of these models a synthetic indicator, represented by a single scalar 3D property accounting for modelled fracture properties and correlated with the expected productivity of future wells. This workflow was applied to a group of fractured carbonate reservoirs in Kuwait which helped in designing new horizontal wells. The developed methodology focuses on capturing accurately the lateral and vertical heterogeneity of

Abstract

Drilling the 121/4-in hole in southern Kuwait usually starts in a shale formation and continues through interbedded sandstone, limestone, and shale. The unconfined compressive strengths throughout the section vary from 6,000 psi to 10,000 psi. The bit types typically used in this section are six-bladed PDC bits with either 16-mm or 19-mm cutters. Because fields in the area are development fields, the main objective for the operator is to achieve the best rate of penetration (ROP) and complete the section as quickly as possible. A common objective was decided on between the operator and bit provider to design a bit to drill the 121/4-in section in one run with ROP above the current benchmark. Different design configurations with different blade counts, cutter sizes, and cutting structures were analyzed using dynamic simulation based on finite-element analysis (FEA). The simulations were run in a dynamic environment to arrive at a design suitable to drill the application. The cutters wer

Abstract

Mature field necessitates drilling high angle and horizontal wells in order to improve wells productivity, reduce water coning and tapping multiple reservoirs. The operating company has endeavored to convert many of the Vertical wells in its mature fields into High angle and Horizontal wells by Side Tracking, primarily to reduce well cost and overcome restrictions in obtaining clear surface locations. Shale instability related problems were experienced in many Side Track wells in the buildup section. The whole deviation used to be ranging from 62 degrees on the top to 70 degrees on the bottom. The old wells used to be completed traditionally with a DLS of 5-5.5 leading to stuck pipe, hole collapse, multiple wiper trips, casing short landing etc. The operating company after extensive techno-economic evaluation has implemented a new and novel drilling technique to allow side tracking from an existing well, with inclination in the hole as low as possible, and land the well successfully wi

Abstract

The Oil and Gas gathering and processing facility of Kuwait Oil Company was built with a nameplate capacity of X MBOPD with 50% water cut. However, the facility was operating with a water cut of 35% since its commissioning in year 2011. This comprehensive technical study was conducted to evaluate possibility of increasing oil processing capacity of this facility in line with current lower water cut and other operational flexibilities available in the facility without utilizing its design margin. This paper shares an innovative approach to increase name plate capacity of oil and gas processing facility utilizing available operational flexibility and operational margins with minor modification. It shares a case study where facility capacity is increased by around 19% without utilizing design margins of equipment or pipeline. Such approach can easily be applied to all similar facilities across oil & gas industry. The study confirmed that facility name plate capacity can be revised from X

Abstract

Kuwait Oil Company(KOC)'s massive expensive efforts, to control extraneous source water invasion, by casing repair in multireservoir ageing wells particularly run by electrical submersible pump(ESP), is not paying expected dividend. To achieve negative casing integrity is a challenge in ageing wells and achievable negative casing integrity is very low (300-900 psi) which does not sustain against ESP's high drawdown (1000-4500 psi) which has been established from workover data accumulated over a prolonged period reveals leakage from previous squeezed zones, corroded/weak casing and liner top. The leakages are refixed with multiple cement squeezes with available recipes. spending a staggering repair cost of $0.5 million USD/well on an average. But after a short span of the potential productive life of the reservoir, significant water production starts from extraneous sources evident from intake pressure and flow rate variation from the reservoir potential, thereby necessitates interventi

Abstract

Directionally drilling of 16-in hole section in a deep gas field had been always a challenging task to the Operator. This is mainly due to the lithology, consisting of very hard limestone with thin bed of shale where the kickoff would generally start around 11,200 ft. The operator attempted to kick off the 16-in hole using both roller cone TCI bit and PDC bit technology and utilizing a mud motor as the drive mechanism. This method provided an unacceptable low rate of penetration. In addition, there were difficulties in achieving the directional control, and multiple bit trips were required to finish the required directional work. The operator determined that a new bottomhole assembly (BHA) would be needed to efficiently drill this section to the desired inclination and azimuth in one run, while meeting the performance requirement. Multi-function teams were organized to aggressively look for new BHA configuration that could consistently drill this interval in one run with a good rate of

Abstract

A reliable liquid rate estimation is critical for evaluation of well and pump performance in wells lifted using electric submersible pumps (ESPs). The estimation of reliable liquid rates is a challenging and complex task even in digital oilfields (DOFs), such as the integrated Kuwait Integrated Digital Field (KwIDF) project in the Sabriyah (SA) field in North Kuwait. The correct liquid rate estimation is necessary to identify the ESP operating point to extend the ESP run life, improve field uptime, and identify production optimization opportunities. Different methodologies have been adopted to provide the most reliable virtual liquid rate estimation: • Real-time rate measurement. • Virtual rate estimation based on well modeling using iterations of wellhead pressure (WHP) and pressure drop across the pump. • Virtual rate estimation based on a well gradient plot using iterations of WHP, water cut (WC), and gas/oil ratio (GOR). • Empirical correlation (tubing head pressure [THP] vs. liqui

Abstract

The North Kuwait Development Project requires a large-hole casing design to isolate problematic formations and enable the operator to reach deep HPHT target zones with maximum hole size. The most difficult section is Zubair to Hith traditionally drilled with 16'' bits. These formations consist of abrasive/pyritic sandstone, reactive shale and carbonates with UCS between 5-30kpsi. Historically, to complete the 3900ft section required more than three PDCs or a combination of 4-5 PDC/TCI. To reduce costs, the first slimhole development well plan and string design was developed for Northern Kuwait fields. The objective would be to downsize the hole section from Zubair to Hith to 9 1/4'' and drill to section TD with three PDCs. The production casing would be run from surface to TD instead of the conventional liner tie-back. To accomplish the objective, the team decided to develop two different 9 1/4'' PDCs: 1) one for Zubair to Ratawi shale; 2) a second for drilling the remaining carbonates

Abstract

This paper describes an advanced methodology for fault and fracture detection using seismic data. The understanding of the fracture network is often necessary for both exploration or production context, as it can be a key driver controlling the fluid movements. In case of highly fractured field, it has to be considered in basin and reservoir models while performing flow simulations or to be taken into account while performing risk analysis for sealing issues. In this paper, we will illustrate the seismic fracture characterization workflow from a study in Kuwait to substantiate this. In this study, in high pore pressure conditions in the formation, the presence of fractures can enhance the drilling risks for future well planning. A dedicated workflow to detect faults and more subtle fractures has been carried out, based on inversion results. The 3D seismic data under study is contaminated with interbed multiple reflections. During the seismic inversion, the Inter-Bed Multiple Modeling (

Abstract

Fluid loss in sub-hydrostatic wells during overbalanced workover operation is a significant concern and includes three different challenges. The first challenge is the near wellbore damage due to the invasion of the completion fluid to the formation. The second challenge is the additional operating cost associated with both rig time spent to pump fluid into the well and stimulation treatment to restore the initial formation condition. The third challenge is maintaining a safe window of overbalance condition during the workover operation which is a major HSE & well integrity concern. The outmoded technique to control losses is to use solids base fluid which could damage the formation if not properly removed after the treatment. Also, in some cases it requires an acid breaker to restore the original formation state. The acid treatment must be done before installing the pump in hole as the solid-fluid system can’t be flow back through the artificial lift. KOC keeps the safety window of th

Abstract

This document describes how the use of filter cake breaking fluid pills in non-cemented completions across North Kuwait Jurassic reservoirs increased the well's likelihood to be stimulated and produced. It describes the process to test this innovative solution before a well trial, the wells and environment in which they have been used, and their impact in the well's ability to communicate the borehole with the reservoir. The initial step was to identify which type of mud breaking pills could be used and available in the industry and use the current OBM dispersant pills as found in cement job spacers to enhance cement-reservoir contact. A target well screening was done to wells with possible non-cemented reservoir completions. The detailed operational procedure was then designed to consider the breaker volumes, the composition of the interface's spacer high viscosity pill, and the weight of the displacement fluid to account for the hydrostatic loss in the solids-free breaker volume into

Abstract

This document describes how the use of filter cake breaking fluid pills in non-cemented completions across North Kuwait Jurassic reservoirs increased the well's likelihood to be stimulated and produced. It describes the process to test this innovative solution before a well trial, the wells and environment in which they have been used, and their impact in the well's ability to communicate the borehole with the reservoir. The initial step was to identify which type of mud breaking pills could be used and available in the industry and use the current OBM dispersant pills as found in cement job spacers to enhance cement-reservoir contact. A target well screening was done to wells with possible non-cemented reservoir completions. The detailed operational procedure was then designed to consider the breaker volumes, the composition of the interface's spacer high viscosity pill, and the weight of the displacement fluid to account for the hydrostatic loss in the solids-free breaker volume into

Abstract

In the current and future scenario of increasing demand for hydrocarbons, Multi-Disciplinary Integrated Waterflood Management team is the key to achieve ultimate recovery. In Raudhatain Upper Burgan reservoir production started in 1959 with initial reservoir pressure of 3850 psi. Decline in reservoir pressure with sustained rate of production indicated weak aquifer support and initiated water injection during the year 2001. With four major flow units, poor sweep efficiency often results from spatial variation and/ or heterogeneity in the permeability of the reservoir rock, usually resulting in an irregular displacement front of the injected fluid. The initial completion design did not address the injection profile control. The integrated waterflood management team initiated number of projects to increase the productivity like Water Flow Regulator technology (WFR). The objective of using this technology is flooding all the units so as to improve the overall sweep efficiency. To optimize

Abstract

Mauddud is a major reservoir in Sabiriyah field, North Kuwait. Mauddud belongs to Middle Cretaceous period with about 350 to 400 feet succession dominated by carbonates deposited in ramp environment. Reservoir is characterized by moderate to high porosity and low to moderate permeability. Detailed variations in lithology and formation fluid are generally beyond the resolution of LWD logs, necessitating collaborative approach from different data source to enhance geosteering and in some cases to test independently and validate geosteering interpretations. High quality geochemical data enabled good correlation of offset wells with current drilled wells. The elemental and mineral analysis in this study was key to build effective pre-job model and to highlight signatures; which was utilized while drilling as a reference to pick critical sublayers. The wellsite geochemical technique enabled to build a robust model, independent from conventional LWD modelling techniques, which resulted in ne

Abstract

Single Well Chemical Tracer Testing (SWCTT) is traditionally performed to determine oil saturation after waterflooding and after enhanced oil recovery techniques. Raudhatain Lower Burgan (RALB) and Sabriyah Lower Burgan (SALB) SWCTT oil saturation reduction due to injection of surfactant-polymer and alkali-surfactant solutions, respectively, were 7 and 8% OOIP, respectively. During SWCTT, injection rate and surface pressure are routinely measured for each injected solution. Injection rate and surface pressure permit additional determinations to be made as outlined below: 1. Pseudo resistance factor to any fluid "i" can be calculated and, from this, changes in injectivity can be determined 2. Flowing viscosity of injected fluids relative to water 3. Effective permeability to injected fluids 4. Injectivity factors Pseudo resistance factor for RALB continually increased with seawater injection, from 0.5 to 1.0 indicating a reduction of kwro to approximately half and a twofold loss of inje

Abstract

The Lower Burgan reservoir in the Abdali field bears extra-heavy oil of viscosity ranging from 8, 000 to 20, 000 cP. In view of its depth, the LBAB reservoir is not amenable to thermal steam-based EOR methods. Non-thermal methods such as polymer-flooding or liquid solvent injection have been investigated. Demonstrating the feasibility of polymer-flooding using ~260, 000 ppm TDS effluent water, under high temperature conditions, can lead to major cost savings in relation to water sourcing and treatment. Extensive lab evaluation was performed to qualify polymers that can withstand harsh salinity and temperature conditions to generate important data for numerical modeling in preparation for potential field implementation. Polymers from four manufacturers were evaluated through viscometry, long-term stability under anaerobic reservoir conditions, resistance to mechanical degradation and injectivity. The reservoir rock structure and mineralogical composition were analyzed before capillary p

Abstract

The vision of each company in the current oil and gas industry scenario is to utilize the existing field investment to increase oil production at minimum cost. Installing sucker rod pumping unit on a dual string well was a big challenge to achieve, especially when the other string was producing naturally. The manuscript focuses on the challenges accompanied with the identification of well needs, designing phase, planning phase and execution phase. Meetings have been held with both field development and well surveillance engineers to discuss the challenges to be faced to install a sucker rod pumping unit. The challenges were to occupy a turn in the rig schedule that have been set for the rest of the quarter, to install the surface unit in presence of a well head set on a high level to meet dual string surface set up and in downhole pump installation to be set through a 3.5- in. tubing with no rig accessThe solution was to use a unique way of installation by utilizing the available equip

Abstract

Aim: This study was designed to detect the accuracy of the insulin-like growth factor binding protein-1 (IGFBP-1) in diagnosing premature rupture of fetal membranes. Materials and Methods: A total of 150 pregnant women after 37 weeks' gestation were included in this study and divided into two groups according to presence or absence of premature rupture of the membranes (PROM); 75 patients with PROM were included in group I and 75 patients without PROM were included in group II as controls. The diagnosis of PROM was based on patient's history of sudden gush of water, pooling of amniotic fluid, positive Ferning pattern, positive Nitrazine test, confirmed by visualization of fluid passing from the cervical canal during sterile speculum examination and transabdominal ultrasound to measure the amniotic fluid index. Results: In this study, the sensitivity and the specificity of IGFBP-1 (Actim PROM test) in diagnosing PROM were 89.3% and 82.7%, respectively, as compared with 84% sensitivity a

Abstract

Objective: To detect the accuracy of the IGFBP-1 in diagnosing premature rupture of fetal membranes. Methods: One hundred and fifty pregnant women after 37 weeks gestation were included in this study and divided into two groups according to presence or absence of PROM; 75 patients with PROM were included in group I and 75 patients without PROM were included in group II as controls. The diagnosis of PROM was based on patient's history of sudden gush of water, pooling of amniotic fluid, positive Ferning pattern, positive Nitrazine test, confirmed by visualization of fluid passing from the cervical canal during sterile speculum examination and Trans-abdominal ultrasound to measure the amniotic fluid index. Results: In this study, the sensitivity and the specificity of IGFBP-1 (Actim PROM test®) in diagnosing PROM were 89.3% & 82.7%, respectively, as compared with 84% sensitivity & 78.7% specificity for Ferning test, and 86.7% sensitivity & 81.3% specificity for Nitrazine test. The PPV and

Abstract

This paper demonstrates the production optimization methodology being usedby Kuwait Oil Company to increase production in one of its giant and mature fields by 20% over 3.0 years. Production optimization is a continuous iterative process to improve production, especially in mature fields. The North Kuwait Redevelopmentteam 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 Typical mature-field challenges are present. These include water flooding, produced water management, artificial lift, with more than 600 (vertical, deviated and horizontal) wells, coupled with high structure complexity and stratigraphic heterogeneity, tight sandstone and carbonate reservoirs, shortage of work-over rigs. These challenges make the fieldappropriate to apply the production optimization methodology outli

Abstract

Free gas along with heavy oil production affects the progressive cavity pump (PCP) performance. This necessitates the strategy to perforate away from the free gas zone. To be able to do this, it requires an integrated approach to evaluate and map the spread of the free gas accumulation in the field. The paper shall present how this resulted in improved well performance with less free gas interference. The methodology included the understanding of the production data, sub-surface geology and petrophysics; reservoir heterogeneity and free gas presence from wireline logs, core data and isotope analysis of gas collected during mud-logging and creation of maps and cross-sections showing both vertical and aerial spread of free gas accumulation. This was then integrated with existing production and well management practices, along with numerical simulation results. Such in-depth analysis helps to bring significant changes in well completion strategy and is a vital contribution to the WRFM str