bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyzing Electric Submersible Pump Failures in the East Wilmington Field of California
Authors: Upchurch E. R. 
Published: December 2007

Abstract
Within the Long Beach Unit of the East Wilmington Field, over 600 electric submersible pumping units (ESP's) are operated from four coastal man-made islands and one pier.
In 1984, an ESP quality control program1 was initiated which ultimately resulted in a significant reduction of ESP failures (Fig. 1). The program required (1) the use of only new rotating equipment in any ESP installation, (2) the testing of all new pumps by the manufacturer, and (3) spot testing of the pumps by an independent testing facility to ensure strict adherence to the program requirements. This quality control program continues to be the primary avenue by which an acceptable ESP run-life average is maintained in the Long Beach Unit of the East Wilmington Field. Fig. 1Recent failure history of the East Wilmington field.
The next step in reducing ESP failures in this field is to determine how the inherent conditions of each reservoir contribute to ESP failure. In so doing, the operating problems that are unique to a certain reservoir condition can be solved. Between January 1, 1985 and March 31, 1989, 1149 ESP's experienced down-hole pumping equipment failure and were subsequently replaced. This case study presents data from the 1149 failures as a function of both the reservoir properties and the pump fluid output and thereby will show the effect of each on ESP failure rates and causes.
The extensive number of low volume ESP's utilized in the East Wilmington Field make it a superb area for the study of low volume failure mechanisms. Low volume wells are considered to be difficult to produce with an ESP primarily because of insufficient cooling of the motor. A minimum fluid velocity past the motor must be maintained to supply adequate cooling. Minimum fluid velocity recommendations, however, vary among ESP manufacturers. These recommendations range from 0.4 ft/s [0.12 m/s] to 1.0 ft/s [0.30 m/s]. A Long Beach Unit well producing 1000 bbl/D [159.0 m3/D] has a maximum fluid velocity of 0.38 ft/s [0.11 m/s] past the motor and, therefore, fits the low volume criteria. Eighty-six percent of the ESP's included in this study pumped less than 1000 bbl/D.
Although ESP's are used successfully in this field, the installations producing less than 400 bbl/D [63.6 rrr/D] do experience higher rates of failure when compared with the higher volume installations. Thirty-seven percent of the wells in this study produced less than 400 bbl/D yet their ESP installations contributed 53% of the failures.
Given the large volume of comparative data available, this study will attempt to provide insight into the causes of both low volume (&lt;1000 bbl/D) and extremely low volume (&lt;400 bbl/D) ESP failures in the East Wilmington Field. Changes in equipment and operational practices to increase run-life will also be examined.
Horizontal Gravel Packing Studies in a Full-Scale Model Wellbore
Authors: Forrest J. K. 
Published: December 2007

abstract
Using full-scale, 45- and 100-foot models, this study shows that better methods are needed for gravel packing highly deviated (&gt;60°) and horizontal wells. Viscous carrier fluids gave incomplete annular packing, particularly around conventional screen connections. In a few tests, better results were obtained by using low-viscosity carrier fluids such as water or a newly developed, two-stage packing technique. An equation was developed that may be used to estimate pack length limits.
Prudhoe Bay Field, Alaska, Waterflood Injection Water Quality and Remedial Treatment Study
Authors: Hsi C. D. , Strassner J. E. , Tucker H. E. , Townsend M. A. 
Published: December 2007

ABSTRACT
A comprehensive laboratory and field study was conducted at Prudhoe Bay Field, Alaska to identify the cause for rapid injectivity decline and injection profile degradation in produced water injection wells and to seek remedial treatment methods to improve water injectivity. A specially designed portable core flow station was installed in the produced water treatment facility at Prudhoe Bay Field to evaluate permeability damage characteristics of produced water on reservoir core plugs and to evaluate performance of different surfactant solutions for restoring water injectivity. Test results show that Prudhoe Bay produced water caused a slow but significant permeability reduction to reservoir cores. Commercially available surfactant solutions were effective initially in restoring water injectivity when applied as slug treatments at 1 to 2% concentration levels. No surfactant solution was effective in preventing damage when injected continuously in the produced water stream at less than 50 to 100 ppm levels. Remedial acid stimulation treatments and solvent washes can restore part of the water injectivity. Study results identify the need to further improve the present produced water treatment facilities.
Growth of Bacteria on Water Injection Additives
Authors: Sunde E. , Thorstenson T. , Torsvik T. 
Published: December 2007

Abstract
In this study, bacteria from oil installations were used in growth experiments with 15 different chemicals normally used in injection water treatment. Growth experiments were performed using a mixture of bacteria grown under aerobic and anaerobic conditions, and SRB pure cultures grown anaerobically.
The results showed that 3 chemicals could be utilized as N-sources, 1 as P-source and 7 as C-sources for bacteria. These chemicals included 1 oxygen scavenger, 3 scale inhibitors, 1 polyelectrolyte, 1 surfactant, 2 antifoaming agents and 2 chelating agents.
The remaining 6 chemicals did not support growth under the test conditions. 5 of these, including 3 biocides, contained nutrients that may be utilized under field conditions.
From this study it is concluded that the growth potential of water treatment additives may be substansial and should therefore be investigated prior to chemical selection.
Application of Subsea Separation and Pumping to Marginal and Deepwater Field Developments
Authors: Baker A. C. , Lucas-Clements D. C. 
Published: December 2007

Abstract
A series of studies has been undertaken in order to quantify the benefits of various alternatives for the remote production of subsea oil reservoirs. Subsea separation and pumping appears to have significant advantages for remote production over longer distances and particularly in deep water. The concept involves the separation of gas and liquids at or near the wellhead; with the liquids being pumped in single phase back to shore, or to a remote production facility, and the separated gas flowing back to the same location under wellhead pressure.
A novel separation and pumping system has been conceived which allows an integrated separator and pump to be installed within a conventional 30" conductor in a dummy well. This novel configuration has been called VASPS (Vertical Annular Separation and Pumping System).
A detailed series of hydraulic studies has been undertaken which indicate that the system is capable of producing over distances up to 100 km and that well deliverabilities are significantly enhanced at increased water depths. We believe this to be a significant conclusion as there is an increased economic incentive to employ remote subsea production in deep water.
The Effects of Non-Darcy Flow in Propped Hydraulic Fractures
Authors: Martins J. P. , Milton-Tayler D. , Leung H. K. 
Published: December 2007

Abstract
Hydraulic fracturing is being applied to progressively higher permeability formations. In many cases, productivity improvements are controlled by the achievable fracture conductivities.
An analysis of the effects of non-Darcy flow in high rate oil and gas wells shows that in gas wells, fracture conductivities are dominated by non-Darcy effects and that effective conductivities are non-linearly dependent on proppant coverage.
Laboratory tests to investigate non-Darcy flow effects in proppant packs have been performed at rates much closer to field conditions than hitherto reported; both single and two-phase flows are considered.
Dry gas tests have demonstrated that there is a change in pressure loss behaviour and flow regime at high rates.
Three types of test involving gas and water flows have been performed. First the effects water-saturated gas flowing in a proppant pack at residual water saturation were compared with results on the same pack with dry gas. Two series of experiments were then performed to examine the effects of mobile water in the gas stream.
Pressure losses are shown to be very sensitive to the water rates, and the field implications are examined.
Finally field data from tests performed on high rate, hydraulically fractured, gas wells are examined. Perceived fracture conductivities are related to estimated proppant coverage, and it is shown that non-uniform vertical distributions of proppant may have a large impact on the overall fracture flow capacity.
Log Evaluation Of Deep Ellenburger Gas Zones
Authors: Neustaedter R.H. 
Published: December 2007

Abstract
Log evaluation of deep Ellenburger gas zones is complicated by the low porosities encountered, and by formation matrix and fluid effects on log responses. In these very low porosities even small inaccuracies in porosity determination produce proportionally large errors in reservoir evaluation.
Each of the logging devices commonly used for porosity measurement—sonic, density, and neutron—is affected by variations in formation lithology and fluid content. While the deep Ellenburger is primarily dolomite, variations in lithology produce inaccuracies in the porosities determined from any one log. Furthermore, gas saturation in the formation close to the borehole affects the neutron and density responses; the neutron gives values of porosity that are too low; the density, too high. While no gas effects have been observed on the sonic response this tool characteristically is pessimistic in zones of secondary porosity. Therefore, no single device reliably affords accurate porosity determination.
The most reliable values of porosity are obtained through a complex interpretation procedure using data from all three logs—sonic, density, and neutron. Computer processing makes this procedure feasible. This computer processing gives not only an improved value of porosity, but also the major lithologic components of the formations, and the gas and liquid saturations of the zones close to the borehole.
Resistivity logs are used in conjunction with the previously mentioned porosity logs. Resistivity values are expressed in terms of bulk volume of water, as in the MOP technique, for comparison with the porosity data.
The analog machine printout of the computed data simplifies the use of logs for formation evaluation and selection of intervals of completion.
INTRODUCTION
The deep Ellenburger gas play is characterized by extremes. The wells are extremely deep—and are correspondingly expensive to drill and complete.
Characterization and Cleanup of Chromium-Contaminated Soil for Compliance With CERCLA at the Naval Petroleum Reserve No. 1 (Elk Hills): A Case Study
Authors: Campbell R. E. , Akers R. T. 
Published: December 2007

Abstract
This is a case study of characterization and clean-up of chromium-contaminated soil at Elk Hills, carried out in compliance with the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA). Elk Hills is a Unit Operation between the U.S. Government and Chevron, USA and covers almost 48,000 acres. It has active production and drilling operations, and produces over 90,000 BOPD and over 360 MMCFD of natural gas. The authors are employees of the Unit Operator (UO), responsible for all aspects of CERCLA compliance at Elk Hills.
Chromium was used as an additive in drilling muds at Elk Hills from the 1950s through the early 1980s at which time its use was discontinued due to its classifications as hazardous waste. In accordance with CERCLA provisions for the identification and remediation of potential past hazardous waste disposal, an identification program was undertaken at NPR-1 in 1986. Through this process, 554 sites were designated at which chromium had been used or may have been used. All sites were inspected, and 62 were found to have some level of chromium contamination. To date, the sites have been remediated and are awaiting confirmation testing to satisfy the Lead Enforcement Agency (LEA) requirement of the cleanup to 1 ppm.
The Austin Chalk: Simulation of Horizontal Wells in a Heterogeneous Formation
Authors: Schnerk G. C. , Madeen C. N. 
Published: December 2007

Abstract
The Austin Chalk is a laterally partitioned reservoir. Horizontal wells penetrate additional partitions that are not produced from vertical wells. The horizontal well data presented in this paper shows that these horizontal wells have currently out produced vertical wells by a factor of five, and additional production is expected. Values consistent with pressure transient testing and core analysis are used to simulate vertical and horizontal wells, and to gain insight into the reservoir mechanisms. Rate derivative curves are used to better understand simulator results.
Modeling Fluid Flow Around Horizontal Wellbores
Authors: Norris S. O. , Piper L. D. 
Published: December 2007

Abstract
Modeling fluid flow around horizontal wellbores with conventional reservoir simulators is somewhat inefficient due to the fact that the radial flow patterns found in the vicinity of the wellbore must be simulated with rectangular coordinate grid-blocks. In this research, we present an efficient hybrid grid model for horizontal well simulation by incorporating radial gridblocks to simulate the radial fluid flow around the wellbore and introduce the concept of spherical gridblocks to model fluid flow around the end of the well. This configuration can dramatically reduce the number of grid-blocks (and therefore computer time) required to accurately simulate the physical model.
The spherical gridblocks consist of hemispheres, corresponding to each radii in the cylindrical coordinate system region, which are intersected by planes that allow coupling to the reservoir region gridblocks. Transmissibilities for the spherical gridblocks are calculated by use of the integrated finite difference method.
Two problems from the literature were chosen to demonstrate the effectiveness of the model. The first problem is a one-phase, constant rate pressure drawdown test for which an analytical solution is available. The second problem is a water cresting problem where the results for comparison were obtained from a commercial reservoir simulator using a grid that reportedly minimized numerical dispersion.
Measurement and Evaluation of Coal Sorption Isotherm Data
Authors: Mavor M. J. , Owen L. B. , Pratt T. J. 
Published: December 2007

Abstract
The proper measurement and interpretation of sorption isotherm data is of primary importance in understanding and predicting the gas production performance of a coalbed methane reservoir. These data are used to predict the release of gas from the reservoir as the pressure is reduced during production and the eventual gas recovery (reserves). A sorption isotherm is a laboratory measurement performed on a representative coal sample to determine the methane storage capacity as a function of pressure. The term "isotherm" results as the experiment is performed at a constant temperature which should be equal to that of the reservoir. This paper presents the use of the data, procedures for performing the measurements, a methodology for interpreting the experimental data for estimates of gas storage capacity and diffusion coefficients of the coal matrix, and isotherms obtained from a variety of coal samples.
Efficient Use of Domain Decomposition and Local Grid Refinement in Reservoir Simulation
Authors: Nacul E. C. , Lepretre C. , Pedrosa O. A. , Girard P. , Aziz K. 
Published: December 2007

ABSTRACT
In order to get desired accuracy in reservoir simulation, one must refine the grid in certain regions, for example, the regions around wells. When this is done in conventional simulators, unnecessary refinement occurs in some regions. This problem is avoided by the use of "Local Grid Refinement" (LGR) techniques, but the resulting matrix is large and of irregular sparsity. In this paper we address several practical aspects of some methods of LGR, including the use of hybrid grid, and then present three highly efficient methods of solving resulting problems with some Domain Decomposition (DD) techniques. In the first method, a relaxation in the unknowns is performed. In the second one, we use overlapping boundaries between the subdomains. In the last one, a coarse grid solution is obtained first and it provides the boundary conditions for the fine grid solution. The LGR and DD methods developed in this work were implemented and tested in a three-dimensional, three-phase, black-oil model. The results are presented in this paper for three examples. It is also shown that the DD technique with overlapping boundaries is extremely efficient for solving problems containing one or more LGR regions. The method proposed in this paper can easily take advantage of parallel processors. Also, it is easy to implement the proposed techniques in existing simulators.
The LGR and DD techniques discussed in this paper improve the accuracy of reservoir simulation around wells and in other regions of high activity. Using these techniques, one not only obtains the correct well pressure, but also the correct saturation near the well. A consequence of this is that WOR and GOR are predicted accurately without well pseudofunctions.
Contractor's Role in Planning Economic Drilling Programs
Authors: Robinson Richard L. 
Published: December 2007

American Institute of Mining, Metallurgical and Petroleum Engineers Inc.

Abstract
This paper reviews some of the pressing problems facing drilling contractors in West problems facing drilling contractors in West Texas. These problems are discussed with the idea of presenting solutions that are economically advantageous to the contractor, and that, in turn, would result in savings to the operator. These ideas largely concern operating procedures in which the contractor's ideas may procedures in which the contractor's ideas may vary somewhat from those of the operator. After there are several ways of doing a certain task, several of which could be equally correct. We believe that closer communication and understanding between contractor and operator could influence ways of accomplishing some operations more economically, the theory being that if an operator can do things to save the contractor money, it will, in the long run, save the operator money.

Introduction
Some phases in drilling a well that bear some review as to equipment requirements and operating procedure are blowout preventor and manifold requirements, deviation limits, and mud programs. Some other problems in which the operator should be sympathetic to the contractor include diminishing labor source, value of lost in-hole equipment while on day work, bid lists and procedures, and reduced volume of drilling.
The main reason for the present plight of the West Texas contractor is an over-supply of rigs, along with a continual decrease in drilling. During the period of the Snyder and Spraberry booms, many people were able to go into the drilling business because of the opposite situation—an under-supply of rigs. The contractor has been paying for the prosperous years since 1957. supply and demand are prosperous years since 1957. supply and demand are approaching a leveling-off point where prudent contractors can make a legitimate profit. Operators now are needed to help establish a sound drilling industry that can worry less about just simple survival and can spend some time, effort, and money in improving drilling techniques.

BLOWOUT PREVENTOR REQUIREMENTS
Vitally needed is for contractors and operators to get together on standardization of blowout preventor manifolds. Coral Drilling, Inc. has utilized approximately 20 different company "hook-ups". Fortunately, they never have lost control of a well kick. This would indicate that the majority, if not all, of their manifolds were suitable. Nevertheless, almost every time there is a change of operators, the manifold must be revamped. The cost of these changes varies, but in the long run it must be recovered from the operators.
Suffield Upper Mannville I Gas Storage Project
Authors: Eresman R. K. , Grant R. A. , Mungan N. 
Published: December 2007

Abstract
The conception, the design, the operation and the performance evaluation of a major gas storage project in Alberta, Canada are described. The observed pressure response during the injection/withdrawal cycles, coupled with new well and seismic data and with new geological and reservoir simulation studies, has given a more complete understanding of the reservoir and its behaviour. A study of the downhole temperature behaviour during injection and withdrawal has also been made. The project is performing successfully and meeting the originally anticipated economic benefits.
Performance of Secondary Gas Recovery Operations: North Alazan H-21 Reservoir
Authors: Cagle T. O. 
Published: December 2007

Abstract
From 1980 until 1989 the North Alazan H-21 reservoir was produced as a Secondary Gas Recovery (SGR) project. Much has been learned during the eight years of project operation. It has proven the technical feasibility of depressurizing watered-out gas reservoirs to reestablish gas productivity.
Computer reservoir simulation was used in the initial evaluation of the SGR project and in a recent reevaluation of the project. This latest reservoir simulation incorporates several refinements over the original H-21 reservoir simulation and has the benefit of history matching actual SGR performance. The computer simulation revealed several interesting results about past SGR operation. It was also used to predict future gas recovery from the project.
Performance Analysis in an Immature Waterflood: The Kuparuk River Field
Authors: Currier J. H. , Sindelar S. T. 
Published: December 2007

Abstract
Waterflood development on 160 acre well spacing has been staged over a period of several years in the Kuparuk River Field. The waterflood is implemented in two distinct reservoir sands which flood at significantly different rates due to differing reservoir permeabilities. This paper presents field data and analysis of waterflood performance in the Kuparuk River Field.
Analysis methods of decline curves, log WOR versus cumulative oil production, and the frontal advance X-plot technique are used and results compared. The importance of analyzing data by well and by zone in this dual-zone flood is demonstrated. The method of plotting log WOR versus cumulative oil recovery and the frontal advance X-plot technique result in very similar projections of ultimate recovery. Interpretation of the WOR versus cumulative oil plots are used to diagnose inadequate pattern performance. Waterflood performance trends indicate that decline curves are harmonic or hyperbolic, showing a decline exponent significantly higher than those suggested in industry literature.
Numerical simulations of C Sand waterflood patterns were performed to model layers of different permeability-thicknesses and match observed behavior. Resulting understanding of the C Sand reservoir description is discussed, as well as the implications to projecting waterflood recovery. This understanding is important to investment decisions in continuing field development, as well as to evaluating the potential of infill drilling and enhanced recovery methods.