bluuebunny/crossref_metadata_2025 huggingface dataset:
Puncak Jaya, Kinabalu Alliance
Authors: Wee S.B. , See K.C. , Edmondson M.W.
Published: December 2007

The Kinabalu Drilling Alliance is named Puncak Jaya. Puncak is Bahasa Malaysia for peak, and Jaya is success, thus Puncak Jaya translates as the Summit of Excellence. The evolution of incentive contracting in SSB/SSPC has seen the introduction of simple bonus and penalty schemes in services contracts at the beginning and of recent the establishment of a tightly knit operations team to address safety, quality and cost performance. The Alliance and Partnering mode adopted for the Kinabalu round I development project of some 8 wells (7 long reach horizontals and 1 multi-lateral) was built upon SSB/SSPC's successful incentive practices over the last 5 years. These include contractual incentive arrangements that addresses plateau performance, quality achievement, project domain consistency, feedback mechanism, target normalisation and bonus distribution. Built into the Alliance Agreement are these custom incentive processes that have driven the various successful incentive contracts such as the Integrated Incentive Contract and the Quality Enhancement Contract (QEC). The Alliance Agreement also has seen the integration of more established practices e.g. mud cost incentive, into their individual contracts during the services contract tendering stage. The incentive mechanisms are simply a means to an end, and for the case of the Alliance, the purpose was to put rewards into place for excellence in teamwork achieving breakthrough bottom line cost performance. The design of Puncak Jaya never wavered from this guiding philosophy and has a peer team of ten partners of which the main drivers are SSPC and the drilling contractor. Each partner actually leads the team when it comes to their area of expertise. This paper describes the incentive structure used and the motivation that each component provides. Important as these are, the critical success factor in an Alliance is instead, the change in working culture that is brought about due to the alignment of goals that these component incentives achieves. Puncak Jaya owes its existence in part to CORAL Malaysia, taking inspiration from the high level teamwork demonstrated and the call for industry wide cost efficiency.

P. 83
Changing the Growth Equation; Integrated Solutions' Contribution Through A Step-Change in Performance
Authors: Reynolds Jim , Pendergraft Bob
Published: December 2007

Widely predicted to be the fastest growing economy of the world for the next 10 to 20 years, the Asia-Pacific and China region can expect significant changes in the upstream energy sector. In response to changing needs, oil companies and solutions providers are searching for new ways of working together to meet the pressing energy demands of what may soon be the world's largest collective economy.

No less vulnerable to the economic demands of the petroleum industry than other world markets, the region's petroleum industry must change to meet the challenge of growing energy demands. As part of this change and as a result of the search for optimum response, the concept of integrated solutions has emerged and moved to the forefront of viable business alternatives. Seeking arrangements where greatest value creation can be achieved, many oil companies are driving service companies into the role of solutions partners. As oil companies shift the emphasis from the delivery of services and products to the provision of solutions, the role of the solutions provider is being defined.

This paper will focus on the alignment of the oil companies' and service companies' interests in integrated solutions. The paper will illustrate how misalignment degrades the value of the solution and reduces the chance of its success. Topics presented will be:–why a step-change in performance is fundamental to the Asia-Pacific and China region–how the various definitions of integrated solutions affect the process of buying and selling integrated solutions–implementation barriers for national oil companies, international oil companies, and the supplier–why integrated solutions are concept based and performance driven–why service companies are capable of delivering integrated solutions–the need for a buyer-protection plan

The paper will conclude with a few observations on the history of integrated solutions in the region and some recommendations for ensuring adequate alignment of the buyers and sellers of integrated solutions.

P. 157
Numerical Simulation and Experimental Studies of Shale Interaction with Water-Base Drilling Fluid
Authors: Huang Hong , Azar J.J. , Hale Arthur H.
Published: December 2007

The pore pressure change and swelling pressure development are two main concerning factors in shale wellbore instability issue. This study investigated water-base drilling fluid interaction with shale formation and the drilling fluid physicochemical effects on shale formation pressure and shale swelling through mathematical modeling, numerical simulation analysis and experimental tests. The study mainly focuses on the drilling fluid pressure, drilling fluid chemical, drilling fluid salinity and shale property effects on shale/drilling fluid interaction. It integrates the water movement into shale with shale pore pressure change, shale water content change and shale swelling pressure development. The experimental tests on shale pore pressure changing with different fluid chemicals have been conducted.

P. 175
Mud Reformulation and Solids Control Equipment Upgrades Improve Hole Cleaning and Reduce Environmental Discharges - A Case Study
Authors: McCollum Frank L. , Kamaruddin Abdul Wahab , Longwell Harry J.
Published: December 2007

A significant number of the wells operated by Esso Production Malaysia, Inc. (EPMI) utilize 12 1/4" production hole and have departure angles greater than 600. As a result of a detailed hole cleaning study, the oil-based drilling fluid was reformulated to reduce the plastic viscosity and yield point to obtain a lower rheology mud to improve hole cleaning. It was found that while the mud could be mixed with the low rheological properties, it could not be maintained effectively when reused over several wells. This finding led to an analysis and upgrading of the solids control equipment on the rigs. The study results that led to mud reformulation, the reformulation itself, and the subsequent solids control equipment upgrades are presented, along with the resulting improvements in drilling efficiency as well as the reductions in the residual oil remaining on cuttings.

P. 325
Case History - Hydraulic Rig Assist Utilized in Workover Program in Dayung Gas Field, Indonesia
Authors: Rachmat Memet , Courville Perry W.
Published: December 2007

The capability to provide workover services on wells without having to kill or balance the well with workover fluid has been one aspect of coiled tubing service that has made it invaluable in the oilfield. However, coiled tubing pipe and units are limited in size, and therefore, are limited in their scope of workover potential. This paper will discuss a scenario in which there was need to provide underbalanced well workovers that could not be performed by coiled tubing.

The Dayung Gas Field in south Sumatra has a reservoir with natural fractures and decreasing mud weight requirements relative to depth changes. Excessive fluid loss is common during the drilling and workover phases of wells in this field. Therefore, drilling and workovers in this field are candidates for underbalanced operations.

Performance of underbalanced operations can assist in the management of problems created 1) by excessive fluid loss in reservoirs prone to lose circulation, 2) in depleted or low pressure reservoirs, which are fluid sensitive, 3) in reservoirs susceptible to skin damage, or 4) by difficulties experienced in killing the well. After consideration of the limitations of coiled tubing and the advantages of performing workovers in an underbalanced condition, the decision was made to review other options.

This paper will discuss the decision-making process employed to select the type of unit to best perform the required services, The paper will also present a case history of the workover project in Dayung with the "wins" of the project, the lessons learned during the project, and the corrective actions taken to enhance job procedures.

P. 371
Ultra-high Pressure Deep Well Drilling Experience in Yingke-1 Well
Authors: Zhu MingLiang , Wang ShengQi , Mao Yuncai , Dong Jie
Published: December 2007

Well yingke- 1 is an overpressured deep well with a depth of 6406m, which contains multilevel high pressure brine water layers and ultra-high pressure gas layers. Its formation pressure is high as much as 140~150Mpa. The well located at Yingjisha structure, southwest of Tarim basin with piedmont structure belt and abnormal ground stress. The paper describes briefly the drilling practice of Yingke-1 well, emphasizing the drilling difficulties and measures that taken. Also, key techniques that should be done in dealing with deep wells and ultra-deep wells under complicated situations in the future are identified in the paper.

P. 401
Real World Implementation of QRA Methods in Casing Design
Authors: Miller Richard A.
Published: December 2007

Conventional casing design utilizes a deterministic approach to compare a maximum load to a minimum performance property. The casing is deemed adequate if it meets a minimum design factor as specified by company practices. Occasionally, a design is proposed that does not meet the company guidelines, often due to material, procurement, or clearance constraints. The engineer must justify deviating from standard practices in order to convince management that the proposed design is still "safe".

Quantitative Risk Assessment (QRA) methods have been proposed as a way to quantify the probability of failure in casing design.1,2 The methods utilize mechanical properties to determine the range of performance that a string of pipe may exhibit rather than a single minimum value. Likewise, a QRA design can include a distribution of possible loads rather than just the worst case scenario. QRA is gaining acceptance in many companies as a way of optimizing casing strings for both cost and safety, especially in critical wells. This paper presents several real world examples where QRA is used to justify casing strings that do not meet conventional design requirements.
On the Development of Reliability-Based Design Rules for Casing Collapse
Authors: Adams A. J. , Warren A. V. R. , Masson P. C.
Published: December 2007

The API design rules for casing collapse1 give widely varying predicted failure probabilities over the D/t range for well tubulars. For low D/t, they give unconservative designs (excessive risk); and for moderate D/t, over-conservative designs (excessive safety).

This paper describes the development of improved design equations, calibrated using structural reliability methods to obtain a uniform predicted failure probability. The new design rules are simpler to use than the existing API equations, and give either safer or more economic design, depending on D/t ratio.
Predicting the Effect of Continued Gas Enrichment Above the MME on Oil Recovery in Enriched Hydrocarbon Gas Floods
Authors: Stalkup Fred
Published: December 2007

Gas enrichment can be an important optimization variable in hydrocarbon enriched gas drive floods. Slimtube experiments often show that oil recovery increases sharply up to the minimum miscibility enrichment (MME) and thereafter increases very little with further enrichment. However, there are physical reasons why oil recovery might continue to improve with increasing gas enrichment above the MME in a reservoir flood:the gas becomes more viscous and more dense from mixing with oil, which improves sweepout,a smaller lean-gas bank develops, which also may improve sweepout, andricher gases may mix less deeply with oil into the multiphase region leaving less miscible flood residual oil behind.

All of these mechanisms are influenced by the physical gas-oil mixing that occurs in a reservoir flood. Unfortunately, a concern with commercial simulators is that numerical mixing or dispersion, which is artificial and non-physical, may dwarf the mixing from physical mechanisms and cause an unrealistic prediction of the effect of continued gas enrichment on additional recovery even if physical mechanisms such as molecular diffusion and dispersion are accounted for in the formulation of the simulator.

This paper investigates the effect of realistic levels of physical dispersion on any increase in recovery resulting from continued enrichment of hydrocarbon gas above the MME. It does this in simplified reservoir-scale cross sections by 1) minimizing numerical dispersion relative to the input physical dispersion by using two-point upstream weighting and a large number of grid blocks, and 2) by approximating longitudinal physical dispersion with numerical dispersion in single-point weighting simulations by making the grid blocks small enough to mimic the physical dispersivity that might prevail in a reservoir. It also attempts to provide insight into the error large grid blocks may cause when gas enrichment is studied with reservoir models.

The results of this study suggest that recovery may continue to improve significantly with enrichment above the MME and that this effect should not be overlooked when optimizing the enrichment of an enriched gas-drive flood. The results also suggest that extremely small grid blocks in the lateral direction may not be required to realistically assess the improvement in recovery with continued gas enrichment if the mixing from the viscous crossflow caused by alternate water and gas (WAG) cycles dominates the numerical mixing caused by moderate-size grid blocks.

P. 51
Application of Reservoir Strength Characterization and Formation Failure Modeling to Analyze Sand Production Potential and Formulate Sand Control Strategies for a Series of North Sea Gas Reservoirs
Authors: Burton R.C. , Davis E.R. , Morita N.
Published: December 2007

A sand control study was conducted for a series of North Sea gas reservoirs. The purpose of the study was to analyze the formation's sand production potential, formulate a sand control strategy and optimize field operations.

This paper discusses field data and documents the methodology used to characterize formation strength from core measurements, conduct formation failure modeling and history match model results with field sand production data. The study was conducted on the Rotliegendes sandstone formation. However, the methodology presented can be applied to any sandstone reservoir requiring formation failure analysis.

The methodology comprises:

Formation Strength Characterization

Measurement of Formation Compressive Strength Correlation of Strength with Petrophysical Data Triaxial Testing

Formation Stress Characterization

Formation Failure Analysis

Formation Failure Modeling History Matching Model Output to Field Failure Data

Development of Sand Control Strategies

Each of these subjects will be discussed with field data presented to support the discussion and subsequent conclusions/recommendations.

P. 159
The Mounds Drill Cuttings Experiment: Determining Placement of Drill Cuttings By Hydraulic Fracturing Injection
Authors: Moschovidis Zissis A. , Steiger Ronald P. , Weng Xiaowei , Abou-Sayed Ahmed S.
Published: December 2007

The paper describes a comprehensive field experiment (the Mounds Drill Cuttings Injection Experiment) to improve our understanding of the mechanics and modeling of the processes involved in the injection of drill cuttings.

Disposal of drill cuttings from offshore, arctic, and other remote or environmentally sensitive locations is of importance from both economic and environmental perspectives. The transportation of such wastes has the potential for accidental spillage of materials in environmentally sensitive locations such as waterways or wetlands. An attractive disposal option (that is coming into more common use) is to inject the cuttings into deep formations where they will not interfere with surface and sub-surface potable water sources. The major issue associated with this technology is to assure that the cuttings are permanently stored and contained and not transported upward to the surface or toward aquifers.

The paper describes the field setting where the experiment is being conducted, the criteria used for formation selection, the technical scope of work, the series of experiments planned and issues which arise when planning and implementing such an experiment.

The test program includes the deployment of fracture imaging diagnostic tools to determine the size, shape and orientation of the created hydraulic fractures and the drill cuttings in the fractures. The diagnostic imaging techniques are microseismic mapping, surface tiltmeters, downhole tiltmeters and surface monitoring of injection fluids, pressures and volumes. Observation of cores from the affected area will provide direct evidence of the fractures to support information inferred rom the microseismic data.

The plan also includes characterization of the mechanical properties of the cores, and laboratory and numerical modeling of the micromechanics of the cuttings injection process.

This experiment is unique in that this is the first time all of these monitoring techniques have been utilized simultaneously at a single location.

The paper will add to the industry's technical knowledge base by providing insight into technical and implementation issues, which arise in planning such a comprehensive experiment. This insight could find applications worldwide for conducting similar field tests.

P. 227
The Development of a New Compact Electrostatic Coalescer Concept
Authors: Urdahl Olav , Berry Pat , Wayth Nick , Williams Trevor , Nordstad Knut , Bailey Adrian , Thew Martin
Published: December 2007

The demand for more cost effective field developments has led to a substantial focus on separation equipment that reduces weight and deck space. Of particular concern are field developments with subsea production templates and multiphase transportation to existing field installations. Additionally, the environmental aspects concerning the use of large amounts of chemical demulsifiers are crucial these days.

In this paper we present a new Compact Electrostatic Coalescer (CEC) that has the capability to reduce both weight and size, and to eliminate the use of chemical demulsifiers, in some cases.

The basic principle of the CEC is the application of a high-voltage A.C. electric field to an emulsion system flowing under turbulent conditions. The influence of both the electric field and the turbulent mixing are utilized in the breaking of the flowing emulsion.

The performance of the laboratory version of the CEC is discussed with respect to emulsion properties, flow rate, applied voltage and residence time in the electric field. Performance is quantified using both a Malvern Particle and Droplet Size Analyzer and a Hamanatsu Image Analysis System.

Some results from a prototype test on live crude are also given.

P. 111
Reducing Emulsion Problems By Controlling Asphaltene Solubility and Precipitation
Authors: Kokal Sunil , Al-Juraid Jamal
Published: December 2007

The precipitation of asphaltenes during crude oil production can cause a number of problems. One problem is the agglomeration of asphaltenes at the water-oil interface and formation of tight emulsions. These asphaltenes can form a thick pad in the dehydration equipment, which can significantly reduce the demulsification rate or increase the demulsifier dosage. Several gas-oil separating plants (GOSPs) in Saudi Aramco have been experiencing such problems.

The paper discusses the emulsion problem in these GOSPs. Several asphaltene dispersants and surfactants were evaluated for their ability to inlubit the precipitation of asphaltenes from crude oils and in reducing demulsifier dosage at the GOSP. Laboratory experiments were conducted to determine the onset and flocculation of asphaltenes from crude oil with and without the dispersants and surfactants. The criteria for asphaltene dispersants/surfactants selection and their application in mitigating emulsions are presented. Certain chemical additives were identified that reduce the agglomeration of asphaltenes at the oil-water interface and enhance the demulsification process when added to regnlar commercial demulsifiers. The mechanism of emulsion stabilization by asphaltenes and other solids is presented.

This paper highlights how a concerted team effort has led to a reduction in demulsifier consumption by 40-50 % in these GOSPs during the past two years. This has resulted in savings of over $500,000 annually. Some of the very tight emulsion producing wells that were shut-in during the winter months are now producing and are expected to do so in the future.

P. 145
Improved Methods for Multivariate Optimization of Field Development Scheduling and Well Placement Design
Authors: Pan Yan , Horne Roland N.
Published: December 2007

Optimization of reservoir development requires many evaluations of the possible combinations of the decision variables, such as well locations and production scheduling parameters, to obtain the best economic strategies. Running a simulator for such a large number of evaluations may be infeasible due to the computation time involved.

This study investigated two multivariate interpolation algorithms, Least Squares and Kriging, to generate new realizations from a limited number of simulations in order to predict the optimal strategies in a field development scheduling project and a waterflood project. The result was a significant reduction in the simulation effort required. The recommended solutions were obtained by searching for the optimal objective function values among the interpolation realizations. Additional simulation runs were performed to refine the search for the final optimal solution in the vicinity of the intermediate optimal region.

The net present value was used as the objective function in both projects. The field development scheduling simulation was achieved by an economic model taking account of all the costs and profits during the time period being studied. In the waterflooding application, movement of the waterfront was tracked and the oil and water production at each production well was calculated, after which the optimum well placement strategy was determined.

The results obtained using the interpolation methods showed that the algorithms are able to reduce the number of simulation runs, to provide a global sketch of the objective function surface, to avoid possible failure at local optima, and to reach the absolute optimum by refining the grids near the intermediate optima. The approaches were shown to be practical, and will be useful in full-scale optimization problems in which simulation costs would be prohibitive for iterative nonlinear optimization methods.
Emulsion Characteristics of High Water-cut Oil Wells
Authors: Janssen P.H. , Harris C.K.
Published: December 2007

A laboratory study was executed which investigated the characteristics of the oil-water-mixture that is produced by a high water-cut well. By means of core-flow experiments the concurrent flow of oil and water in the near-wellbore region of a high water-cut well was simulated. Production parameters and formation and fluid properties were varied in the experiments. The effluent of the different types of cores produced a mixture of large millimeter-sized drops and micro- droplets which were typically of the order of the pore size. The size distribution of the produced emulsion droplets was measured by a particle size analyzer, based on laser diffraction.

The experimental results revealed that the droplet diameter produced by different sandstone cores was a unique function of pressure gradient and interfacial tension and independent of the type of sandstone.

Furthermore it was observed that wettability has a strong impact on the type of oil-water morphology.

P. 405
Horizontal Well Performance Evaluation and Fluid Entry Mechanisms
Authors: Lenn Chris , Kuchuk Fikri J. , Rounce Justin , Hook Peter
Published: December 2007

In this paper, the use of various measurements is presented for performance evaluation of horizontal wells. The importance of formation evaluation and the challenges of testing in horizontal wells are reviewed. Factors affecting the productivity of horizontal wells are explored. The difficulties in horizontal well productivity estimation due to their long length in the formation compared with vertical wells and inadequacy of measurements during drilling and production are shown. It is also shown that how reservoir heterogeneity affects the reservoir pressure distribution and hence fluid entry profiles and well productivity. Using field examples, we show that the new integrated production logging measurements can be used to assess horizontal well productivity by identifying productive zones, fluid entries, and determining the fluid distribution (oil, gas, and water) in the well- bore. A range of fluid entry mechanisms from over twenty recently logged wells are described and classified. The continuing development of production logging technology for horizontal wells is described. The field examples indicate that horizontal wells have permanent water sumps, regard- less of whether they produce water or not, which leads to reduced oil entry. Performance simulations have shown that for these horizontal wells a 30 to 50 percent productivity (PI) reduction is found when they are compared with their full potential.

P. 365
Multiple Hydraulic Fracturing of Deep Gas-Condensate Wells in Oman
Authors: Jones A.T. , Al Salhi M.S. , Al Shidl S.M. , England M. , Pongratz R.
Published: December 2007

This paper describes the design, execution, and analysis of multiple hydraulic-fracturing treatments in deep gas-condensate wells in Oman. Improved fracture performance is being aggressively targeted to increase well productivity and reduce the number of wells initially required for the contractual production capacity of Oman's LNG plant that is currently under construction. In addition to using conventional fracture processes, engineers optimize fracture design by using both state-of-the-art dynamic gas-condensate reservoir modeling and fracture geometry modeling. They also analyze well-test data and discuss operational experience.

P. 437
Pioneering Subsea Intelligent Completion Installations - Aquila Case History
Authors: Marangoni M. , Giuliani C. , Botto G. , Ferrario G.
Published: December 2007

For those who are not familiar with the concept, intelligent completions are one of the hot topic of today's well completion technology.

The idea is that control of production parameters is done more effectively and efficiently at reservoir level possibly without or with a minimum of direct well intervention. Thus, the design of ‘intelligent’ systems that allows remote manipulation via a control umbilical of devices permanently installed downhole.

The technology is today in its infancy but it is fuelled by great expectations from the oil industry.

This paper provides the case history, from the background of early engineering to the field deployment, of one of the pioneering application: the first intelligent completion in a subsea environment.
New Exact Spherical Flow Solution with Storage and Skin for Early-Time Interpretation with Applications to Wireline Formation and Early-Evaluation Drillstem Testing
Authors: Proett Mark A. , Chin Wilson C.
Published: December 2007

The wireline formation tester, which is frequently operated over short durations, and a new formation testing tool that obtains pressure measurements during the drilling program, have provided the impetus to develop improved pressure transient analysis methods that support formation evaluation during early-to-intermediate test times. Existing methods, for example, apply to late times only, and are approximate in that they do not model the entire timewise pressure response; alternatively, the detailed models that are available for more exact analysis are numerical, chart-oriented, and not amenable to simple physical interpretation.

This paper extends recent work that has solved the spherical flow boundary value problem for storage with an exact analytical solution.1,2 Here, the general spherical flow formulation, including both wellbore storage and skin effects, is solved by inverting the complete Laplace transform to produce an exact, closed form, analytical solution. This new solution reduces to previously published early- and late-time solutions in the respective asymptotic limits. However, the new solution permits convenient pressure response to theory matching over the complete time regime (early-, transitional-, and late-time data), rather than conventional late-time, spherical flow matching; it permits critical pressure-transient interpretation using only early-to-intermediate-time data, thereby reducing required rig time.

The new solution is derived for the full initial-boundary value problem for transient, compressible, spherical flow using Laplace transforms. Closed-form expressions are obtained for pressure, pressure derivative, and sandface flow rate in terms of complex error functions. These exact solutions are compared to existing spherical solutions obtained by numerical transform inversion, and also to finite element results that include the three-dimensional effects of wellbore geometry.

The accuracy and interpretation speed of the new solution permits systematic determination of all flow parameters, to include storage coefficient, skin effect, formation fluid compressibility, permeability, and pore pressure. Its application to a new type of well test tool designed for pressure testing during the drilling program is described. Synthetic data from wireline formation testers and a new drill pipe conveyed pressure test system are analyzed to illustrate the utility and power of the new solution. These examples are used to demonstrate how the new approach can improve real-time regression analysis used in determining formation properties.
Lessons Learned from 4D Projects
Authors: Waggoner J.R.
Published: December 2007

Time-lapse 3D, or 4D, seismic has been under consideration by the industry for reservoir monitoring for more than a decade. It offers the possibility of identifying the inter-well distribution of bypassed and untapped oil, of monitoring displacement heterogeneity, and of detecting uneven pressure depletion away from wells. If obtained, these detailed observations could be used to increase ultimate recovery, reduce production costs, and prevent surprises such as unexpectedly early breakthrough.

But these benefits are not easily obtained, and are certainly not guaranteed. There are a number of factors that impact whether a 4D project will be successful, and a careful study of these is required to give a realistic expectation of what 4D can do for a specific reservoir. Numerous 4D seismic projects have been active over oilfields world-wide, and successes, relative to each project's objectives, have been realized by field operators using a wide variety of data acquisition techniques (land, streamer and seabed methods), and over a variety of field types, including both clastics and carbonates.

This paper draws from this experience to present a generalized 4D project workflow, and reviews results from some of these recent projects as illustrations. In general, sufficient software tools, rock physics data, and experience now exist to conclude that 4D is a low risk/high benefit reservoir management tool. The key to a successful project, however, is determining what 4D can do in a specific field, which requires a careful feasibility study, clear reservoir management objectives, and high quality and experienced seismic processing and interpretation.

P. 509
Improvement and Sensitivity of Reservoir Characterization Derived From Time-Lapse Seismic Data
Authors: Huang Xuri , Meister Laurent , Workman Rick
Published: December 2007

In general only a single 3D seismic data set is used for the characterization of the static properties of a reservoir, even though these static properties could be integrated with dynamic properties. But sometimes, more than one 3D seismic data volume has been acquired over the same field after the production starts. We propose to use these additional data not only to understand the dynamic properties of the reservoir using a time-lapse seismic analysis as presented last year, but to improve the accuracy of the initial reservoir description and study its sensitivity to the input data during the optimization process. Using two 3D seismic data sets acquired over a field in the Gulf of Mexico, this paper demonstrates a method to improve the porosity map obtained from the geostatistical characterization of the base 3D seismic data set by an analysis of the second 3D data volume. It is not possible using just the base data to differentiate factors such as fluid content and pressure from the geostatistical porosity characterization. But by using the flow information from the wells and the second 3D seismic data which was acquired after the production started, it is possible to decouple the porosity, fluid contents and even pressure. Consequently, it provides a more representative porosity characterization compared to using a single 3D seismic data set. The relative permeability curves are optimized by comparing actual time-lapse seismic and production data to synthetic ones generated with a Gassmann rock physics model.

P. 527
Booking Reserves
Authors: Ross J.G.
Published: December 2007

Inconsistency in approaches used for booking reserves, whether for internal or external reporting requirements, represents a significant problem for the industry. Despite all the efforts made in attempting to establish a broadly acceptable set of reserve definitions and the guidelines published by various regulatory bodies, there are many areas where different interpretations are adopted and, therefore, the key requirement of any system - consistency - is not achieved. Inconsistency occurs at two fundamental levels: firstly, in the interpretation as to what is meant by "reserves", particularly with respect to commerciality; and, secondly, what volumes should be booked in specific circumstances (e.g. under production-sharing contract terms, where non- hydrocarbons are present, where hydrocarbons are used on-site for fuel, etc.).

The first problem may be addressed by an integrated resource reporting system which ensures that reserves are seen in their correct context as discovered, commercial, recoverable, remaining resources, while the new SPE/WPC definitions provide a basis for the system, additional definitions and guidelines are required to ensure an acceptable level of consistency is achieved. The second area of difficulty is related to the actual volumes that are booked. This is an issue which has not been addressed adequately to-date. A series of "guiding principles" are proposed as the basis for discussion and debate, in the hope that it may lead to an improved understanding of the problem and, ultimately, much greater consistency in the booking of reserves.

P. 561
Characterization of a Vertically Compartmentalized Reservoir in a Supergiant Field, Burgan Formation, Greater Burgan Field, Kuwait; Part 1: Stratigraphy and Water Encroachment
Authors: Kirby Robert H. , Carr Brian S. , Al-Humoud Jamal , Safar Ahmed I. , Al-Matar Dawood , Naser Waleed
Published: December 2007

This is the first of two papers which describe a comprehensive multidisciplinary effort toward reservoir characterization in the Greater Burgan field. In early 1995 a team of geologists and engineers began reviewing and evaluating Greater Burgan data in order to build an integrated reservoir model. This paper describes the interpreted depositional history of the Burgan formation, relates water encroachment in the reservoir to the stratigraphic architecture, and discuss the potential for oil migration between the main reservoir units.

P. 509
Analyzing Well Production Data Using Combined Type Curve and Decline Curve Analysis Concepts
Authors: Agarwal Ram G. , Gardner David C. , Kleinsteiber Stanley W. , Fussell Del D.
Published: December 2007

This paper presents new production decline curves for analyzing well production data from radial and vertically fractured oil and gas wells. These curves have been developed by combining Decline curve and Type curve analysis concepts to result in a practical tool which we feel can more easily estimate the gas (or oil) in place as well as to estimate reservoir permeability, skin effect, fracture length and conductivity, etc. Accuracy of this new method has been verified with numerical simulations and the methods have been used to perform analyses using production data from several different kinds of gas wells. Field and simulated examples are included to demonstrate the applicability and versatility of this technology.

Decline curve analysis methods, in a variety of forms, have been used in the petroleum industry for more than fifty years to analyze production data and forecast reserves. Type curve analysis methods have become popular, during the last thirty years, to analyze pressure transient test (e.g. buildup, draw-down) data.

Pressure transient data can be costly to obtain and may not be available for many wells, while well production data is routinely collected and is even available from industry data bases. In the absence of pressure transient data, a method that cause readily available well production data to perform pressure transient analysis would be very beneficial. The result is the development of these new production decline type curves.

These new production decline type curves represent an advancement over previous work because a clearer distinction can be made between transient and boundary dominated flow periods. The new curves also contain derivative functions, similar to those used in the pressure transient literature to aid in the matching process. These production decline curves are, to our knowledge, the first to be published in this format specifically for hydraulically fractured wells of both infinite and finite conductivity. Finally, these new curves have been extended to utilize cumulative production data in addition to commonly used rate decline data.

P. 585
Well Evaluation Using Early Time Post-Stimulation Flowback Data
Authors: Crafton James W.
Published: December 2007

Accurate measurement of all produced fluids and solids during the post-stimulation flowback following an acid or hydraulic fracturing stimulation, and the flowing wellhead pressure on a frequent basis provide the data necessary to assess several valuable reservoir, completion and stimulation parameters. The qualitative and quantitative analysis is performed using the Reciprocal Productivity Index procedures. Most flowback data sets will have sufficient quality to provide good estimates of the contributing effective permeability-thickness, the apparent fracture half-length or effective wellbore radius and unusual reservoir pressure conditions. Qualitatively, the evaluation provides information on effective or damaging flowback management strategies, such as the effect of shut- ins, or excessive drawdown during flowback and the duration of flowback necessary for maximum clean-up. It also provides a means of assessing multi-stage stimulation results and productivity profiles within the well. Although downhole data is always desireable, the method is effective when only surface data is available because of risk or cost issues. Examples are provided to demonstrate several of these situations, in addition to a brief discussion of causative factors.

P. 599
Design of a Cased-Hole-Density Logging Tool Using Laboratory Measurements
Authors: Moake G.L.
Published: December 2007

Density tools provide valuable information required to locate gas and evaluate formations. Although 200 Tcf of gas resources are estimated to exist behind pipe in the U.S. alone, present-generation density tools are unable to deal with the magnitude of cement thickness that is typically encountered in a cased borehole. Thus, use of these tools is generally restricted to open boreholes.

This paper describes the design study, partially funded by Gas Research Institute, to be used in developing a density tool capable of providing consistent, reliable measurements in a cased-hole environment without prior knowledge of the casing or cement properties. A special laboratory tool was constructed to acquire data used to develop the design.

In studying the variables relevant to a cased-hole density measurement, it was noted that the density and composition of steel casings are very uniform and thus do not need to be addressed. Also, measurements with normal and hematite-loaded cement showed that the composition of the cement is not significant. Similarly, the elemental composition (lithology) of the formation is expected to be unimportant. Consequently, the tool response is determined primarily by four variables: formation density, casing thickness, cement thickness, and cement density.

Analysis of measured gamma-ray spectra indicated that the spectral shape contains little information about the variables that is not contained in the total count rate. Therefore, four detectors are required to evaluate the four variables when the variables are independent. When cement thickness is small, the four primary variables are not independent, and only three detectors are required to determine the formation density. However, analysis of an optimized three-detector tool indicated that such a tool would not be accurate for cement thicknesses much greater than an inch. On the other hand, analysis of an optimized four-detector tool indicated that the design would make quality measurements through up to two inches of cement. A cobalt-60 logging source, which is more penetrating than cesium- 137, is used to improve precision and depth of investigation.

P. 565
Need Stress Relief? A New Approach to Reducing Stress Cycling Induced Proppant Pack Failure
Authors: Rickards Allan , Lacy Lewis , Brannon Harold , Stephenson Chris , Bilden Dean
Published: December 2007

Stress cycling of proppant packs often occurs during well production operations and is known to be a major contributing factor to proppant pack failure. Proppant crushing occurs due to increasing closure stress as a well is drawn down. The fines generated by such crushing can cause significant damage to proppant pack porosity and fracture conductivity. Additionally, the incidence of proppant flowback (fines and whole proppant) has been reported to be exacerbated by stress cycling.

The addition of deformable beads to the proppant pack has been observed to alleviate both problems and may significantly improve well performance. Testing of various mixtures of the deformable beads and proppant has demonstrated significant reductions in the amount of fines generated and accompanying improvements in proppant pack permeability. Furthermore, the initiation of proppant flowback was observed to require much higher flow rates than in the absence of the beads.

It is thought the process of bead deformation serves to "cushion" the proppant particles from the full brunt of the stress. New laboratory facilities and procedures have been established to study and quantify, proppant flowback, and conductivity as a function of proppant, temperature, flow rate. fracture width, closure stress, and cycle frequency.

P. 659
Successful Application of High GOR ESPs in the Lekhwair Field
Authors: Brinkhorst J. W.
Published: December 2007

The Lekhwair Field, producing from a hydrostatic pressured carbonate reservoir, containing a light under-saturated oil, has been developed using gas-lift as the primary lift method. As process facilities have recently become gas constrained the use of Electrical Submersible Pumps (ESPs), as an alternative lift method to reduce compression requirements, has been proposed and trialled. The production conditions require free gas volumes of up to 80% to be handled by the pump down-hole. To achieve this it is essential that an effective gas separator is installed below the pump. Several ESP vendors (REDA, Centrilift and ESP Inc.) have been approached for their preferred solution. Three different ‘ESP / gas separator configurations’ have since been successfully installed in 6 wells. Establishing the right well design criteria and well productivities up front is essential for the successful application of High Gas Oil Ratio (HGOR) ESPs, guaranteeing a long run-life. This paper discusses the main design criteria applied, compares the performances of the actual pumps installed and discusses the various conditions of influence on pump behaviour.
Field Advanced Water Control Techniques Using Gel Systems
Authors: BAYLOCQ P. , FERY J. J. , GRENON A.
Published: December 2007

In the past few years, gel treatments have been considered to have an interesting potential for water shut off applications and improvement of the near wellbore injection profiles. This paper describes different applications using several types of gels, and details the lab and field procedures to ensure an efficient treatment.

Polyacrylamide crosslinked gels have been successfully used to seal a water zone in a sandstone allowing the production of a bottom gas layer or to improve the conformance of the near wellbore injection profile in naturally fractured carbonates. Silicate gels were also used in the Middle East to shut off, during the drilling phase, several high pressure water flooded layers in order to avoid any crossflow between layers during the cement setting and the production phase.

This paper describes some of the gel evaluation laboratory tests and different field applications. Procedures and recommendations for a proper formulation selection and an efficient gel placement are also presented.
Zadco Experience In Stimulating Multi-Lateral Wells Offshore Abu Dhabi
Authors: Hassan M. M.
Published: December 2007

The result of horizontal trial programme adopted by Zakum Development Company (ZADCO) during 1989 was encouraging from operational and reservoir management viewpoints. Subsequently, most of the wells have been drilled as dual/ multi-lateral wells and barefoot completed with dual tubing strings. Hydrochloric acid (15%) was used to remove the formation skin damage and restore the natural permeability of the reservoir. The acid was pumped into the lateral holes using two types of diversion techniques:

Controlled Diverting Chemicals (CDC) which is a linear gelled system that works on pH value.

Gelled Foam Water (GFW) which depends on the presence of foam bubbles that create a multiple film face in the well bore.

This paper presents the different completion methods where the setting depth of the production casing is important for better stimulation jobs.

Also, it highlights in details the stimulation design, technique and procedure along with the evaluation of acid jobs based on surface measurement, well's production performance and production logging results.
A Petrophysical and Petrographic Study of Carbonate Cores from the Thamama Formation
Authors: Ramakrishnan T.S. , Rabaute A. , Fordham E.J. , Ramamoorthy R. , Herron M. , Matteson A. , Raghuraman B. , Mahdi A. , Akbar M. , Kuchuk F.
Published: December 2007

This paper was prepared for presentation at the 8th Abu Dhabi International Petroleum Exhibition and Conference held in Abu Dhabi, U.A.E., 11-14 October 1998.
Tertiary Gas Injection: From Pilot to Full Field - A Case History Offshore Abu Dhabi
Authors: Nicolle G. , Cartier G. , Jaber O.
Published: December 2007

This paper was prepared for presentation at the 8th Abu Dhabi International Petroleum Exhibition and Conference held in Abu Dhabi, U.A.E., 11-14 October 1998.