bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Total-Velocity Sequential Preconditioner for Solving Implicit Reservoir Simulation Matrix Equations
Authors: Watts J. W. 
Published: December 2007

Abstract
The total velocity sequential semi-implicit method has received significant use since it was originally developed in about 1970 by Spillette, Hillestad, and Stone1. Its advantage is a reduction in the per-timestep computational requirement. It comprises two major steps: a solution of the IMPES pressure equation, then a solution of coupled saturation equations. Since the pressure solution is for a single unknown at each gridblock, it requires less work than solving fully implicit equations. Since the set of saturation equations does not have the elliptic nature of the pressure equation or of the fully implicit coupled set of equations, the saturation solution converges rapidly. Overall, the per-timestep computational work required is typically a half to a fifth that required for fully implicit computations.
The sequential semi-implicit method is far more stable than IMPES, and it can be effective in a wide variety of reservoir problems. However, there are problems in which it does not work as well as the fully implicit method, its per-timestep economy being more than offset by a requirement to perform more timesteps.
This paper describes an attempt to get the best of both worlds by using the total velocity equations in a preconditioner for the implicit matrix equation. The resulting method, which is similar to CPR2, has performed effectively in a variety of problems. However, its performance has not yet been compared to that of competing methods.
Implementation of the Modular Magnetic Tool in Air Drilling Systems
Authors: Morsy Hatem , Shale Les 
Published: December 2007

Abstract
Conventional methods used to steer the BHA when drilling with air are primitive and time consuming. Usually, a single shot survey tool is the most convenient option for steering the BHA.1 Survey tools, however, are not designed for the harsh environment. Consequently, they are prone to early failure in this application. To improve reliability and drilling efficiency in air and gas drilling, the Modular Magnetic Tool (MMT) was developed. The MMT employs a rugged steering tool with a wet-connect system. This MMT/Wet Connect System allows orientation of the drilling motor in a particular direction while still allowing drilling straight ahead with drill string rotation.
The steering tool was specially designed to handle the high shock and vibration when drilling with air and gas. It provides continuous surface readout of drift angle and azimuth of the hole as well as tool face orientation while drilling ahead.
The wet-connect system allows the wireline to be run through the drill string from the top of the Kelly. Connection of the wireline employs a male end (rocket) that sits in a special sub in the drill string. A female end stabs onto it whenever it is desirable to orient or survey. The female end can be tripped out of hole inside the Kelly, either to make a connection or to allow rotation of the drillstring. This configuration minimizes both down time and damage to the wireline that could be critical when drilling in certain formations.
This paper discusses system design and performance, and presents case studies of wells drilled utilizing this system.
Novel Completion Brine Applications at Viosca Knoll in Hot, H2S and CO2 Environment
Authors: Darring M. T. , Moore K. R. , Ali S. A. , Vollmer D. P. , Ke M. 
Published: December 2007

Abstract
A novel non-halide completion brine has been developed and field tested in the Viosca Knoll field, offshore Mississippi and Alabama in the northeastern Gulf of Mexico. Laboratory testing was performed to confirm the non-corrosive nature of the novel completion brine in a high-temperature acid-gas environment. Testing was performed on 4130 carbon steel and 13 chrome stainless steel at 320°F to simulate conditions anticipated in the 15,000' Viosca Knoll wellbores. These conditions include up to 3.5% CO2 and 35 ppm H2S in the produced gas. Results of long-term weight-loss corrosion tests are presented, as are data from return permeability core-flow studies.
Case histories for three wells are presented, specifically those in which the non-halide completion brine was used as a packer fluid and as a perforating fluid. Some of these wells were first flow-tested by perforating in water-base drilling mud. An examination of the data from these wells confirms the benefits of perforating in the non-halide completion brine into the limestone reservoir.
Unusual precautions are required in blending, handling and transporting the brine. This paper also outlines some of the special measures used and recommended for handling.
ESP's: On and Offshore Problems and Solutions
Authors: Lea James F. , Bearden John L. 
Published: December 2007

Abstract
This paper is a follow-on to SPE 28694 (Ref. 180) which summarizes and categorizes ESP literature by a number of different topics. The intent is to list problems mentioned in various papers and a quick mention of the solutions, which are discussed in the given references. As mentioned in the previous reference, it is also an attempt to relate problems to various field conditions, however many of the field papers do not include a complete listing of field conditions, so to be able to do this from using the literature is often not possible.
Can Electrical Insulation and Conductor Performance Be Predicted?
Authors: Durham Marcus O. , Durham Robert A. 
Published: December 2007

Abstract
Long power cables and large machines require different application techniques from most electrical wiring. The first topic discussed is a new technique for evaluation of insulation for continued use. The second area is a different method for selection of conductor size considering temperature and voltage drop. The hi-pot evaluation is primarily a maintenance function, while the voltage drop procedure is primarily a design practice.
For the first topic, high potential (hi-pot) tests are often conducted on power cables and large machines. However, there has been no standardized method of determining if the insulation is acceptable. Various methods have tried to compare leakage current between conductors, use a fixed limit on leakage current, or compare with previous tests. Each has its advantages and limitations.
From empirical data and diverse experience, we have developed a numeric technique that will indicate impending failure. The procedure is mathematically rigorous but can be practically applied. It is very applicable to computer controlled hi-pot systems as well as manual systems.
The second topic is the voltage drop for long conductors. We have applied numerous considerations to develop a simple relationship that can be readily applied. It incorporates wire diameter, length, current, number of phases, and temperature correction, with permissible voltage drop.
Quantitative Model of Wormholing Process in Carbonate Acidizing
Authors: Gong M. , El-Rabaa A. M. 
Published: December 2007

Abstract
Wormholing in carbonate acidization is a dynamic process that involves competition between a couple of physical and chemical processes such as convection and mass transfer as well as surface reaction. Acid injection rate, reaction rate, and molecular diffusion rate all affect the wormhole creation and penetration.
A new quantitative wormhole model is presented to describe the wormholing process in carbonate acidizing. Unlike other models, this comprehensive model deals with the wormholing process by introducing various acidizing dynamics, including acid reaction, diffusion, and convection. Therefore, both the Damköhler number and the Peclet number are involved in the model.
With pertinent physical parameters, the model predicts the wormhole length as a function of acid injection rate when both rock and acid properties are known. Comparing with extensive experimental data of linear core flood in both limestone and dolomite, the model accurately predicts the wormhole breakthrough time. More importantly, the critical injection rate (or optimum injection rate) is obtained with the model by differentiating the equation with respect to the injection rate. The ability to estimate the critical injection rate enables field carbonate acid treatments to be more efficient.
For practical applications, the model is properly extended to 2D and 3D radial flow geometry by introducing fractal dimensions. At last, the paper presents examples applying the wormhole model to field applications including open hole and perforated hole. Based on theoretical and experimental studies, suggestions are given for the optimization of field carbonate acid treatment.
Production Optimization at the Kuparuk River Field Utilizing Neural Networks and Genetic Algorithms
Authors: Stoisits R. F. , Crawford K. D. , MacAllister D. J. , McCormack M. D. , Lawal A. S. , Ogbe D. O. 
Published: December 2007

Abstract
The Kuparuk River Field, located on the North Slope of Alaska, contains approximately 6.4 billion barrels of oil. Total cumulative production to date is approximately 1.4 billion barrels, and current average daily production is 270,000 barrels of oil. The total number of wells in the field is approximately 900. Oil, water, and gas are separated at three Central Processing Facilities. Gas is compressed at each facility for use in gas lift operations and for miscible and immiscible water alternating gas pressure support projects. Kuparuk is production facility limited, which imposes gas, and water handling constraints on the field. Allocation of wells to the production facilities as well as allocation of lift gas are key elements in maximizing oil production rate. An optimization program utilizing formation gas oil ratio and incremental gas oil ratio computations for well and lift gas allocations is currently in use.
The objective of this work was to develop an optimization model which would be an improvement over the current model and also be superior to commercially available optimization software. This required the development of a field production model which included well performance, surface line, and facility models. For each iteration in the optimization model oil rate from the field production model is computed. Two major impediments to the rigorous optimization of large producing fields are the effectiveness of the optimization algorithm and the cost of computing the state of the objects being optimized. In order to successfully solve for an optimal solution to this large highly nonlinear allocation problem a technique based on genetic natural selection process is used. In order to address the problem of excessive computation time neural networks were developed to replace the surface line hydraulics simulation.
The new optimization program was evaluated using twenty-seven days of field data. The average daily production rate based on the 27 days of information was 273,000 bopd. The program was run in predictive mode and yielded an average 272,000 bopd for these 27 days. This indicated the field production model was reasonably accurate. The program was then run in optimization mode to generate recommendations for allocation of wells to production and allocation of lift gas. Average forecasted optimized rate for the 27 days was 292,000 bopd, which is a 7% increase in production over the current optimization forecast method.
Economic Pilot-Floods of Carbonate Reservoirs Using a Pump-Aided Reverse Dump-Flood Technique
Authors: Yao C. Y. , Hill N. C. , McVay D. A. 
Published: December 2007

Abstract
Successful waterflooding in carbonate reservoirs depends greatly on the ability of the operator to make technical and economic adjustments in a specific area, due to the heterogeneous nature of carbonate reservoirs. It is important to systematically consider all tools available in waterflood system design, including laboratory testing, waterflood design using computer simulators, pilot flood tests and waterflood monitoring 1.
This paper presents a case study of a 5-injection well pilot flood in three carbonate reservoirs in the Onbysk oil field using a pump-aided reverse dump-flood technique. This technique was optimal given the conditions at the remote Onbysk field: no surface injection facilities and little data available on water flooding carbonates in adjacent fields. The feasibility study includes laboratory core flood tests, waterflood computer simulation using a 3-D reservoir simulator, and a 5-injection well pilot flood in three domes. This 1-1/2 year reverse dump-flood pilot project indicates that water flooding is economically feasible in these carbonate reservoirs; thus, a large-scale surface water injection program was started to maintain reservoir pressure and to increase reserves.
Effect of Wettability and Matrix to Fracture Transfer on the Waterflooding in Fractured Reservoirs
Authors: Civan Faruk , Wang Wei , Gupta Anuj 
Published: December 2007

Abstract
Effect of matrix-to-fracture transfer on oil displacement by water imbibition in naturally fractured porous media is investigated in terms of the wettability effects and the governing rate processes. A mathematical model is developed by coupling the two-phase flow in the fracture network and in the porous matrix via an oil-water exchange function that incorporates the rates of transfer of oil from the dead-end pores to the network of pores and then to the network of fractures. The resulting integro-differential equation is solved numerically. The parametric studies carried out utilizing this model indicate that the rate constants and matrix wettability play important roles in obtaining an accurate description of the oil recovery during waterflooding in naturally fractured reservoirs.
Improved Blowcase Operation and Design
Authors: Elmer William G. 
Published: December 2007

Abstract
Blowcases have been used in the oilfield for many years to transfer fluids, but how do they work? What characteristics distinguish a well-designed blowcase? Do blowcases have a future? This paper answers these questions by:
Discussing the role of blowcases, and in what circumstances they may be preferred to pump operation, Explaining the process flow diagram for a typical blowcase, Reviewing typical styles of level controls, floats, and motor valves used for blowcase operations, Calculating the ratio of displacement gas to fluid removed for two level control designs, Calculating blowcase efficiency for two level control designs, and Discussing the advantages and disadvantages of small versus large volume blowcases.
The conclusion will be made that blowcases will continue to play an important part in oilfield operations, and that better understanding of blowcase "Best Practices" would be beneficial to industry.
Static/Dynamic Settling of Proppant in Non-Newtonian Hydraulic Fracturing Fluids
Authors: Asadi Mahmoud , Shah Subhash N. , Lord David L. 
Published: December 2007

Abstract
Experimental data and analysis are presented on the static and dynamic settling of proppant in non-Newtonian hydraulic fracturing fluids. A unique High Pressure Simulator (HPS) that closely models reservoir hydraulic fractures is used to study proppant-settling behavior under both static and dynamic conditions. A system of optical fibers and Light Emitting Diodes (LED) acting as a vision system were imbedded in the platens representing fracture walls for quantification of proppant settling under various fluid injection conditions.
Hydraulic fracturing fluids tested include slurries of 35 lb/Mgal guar linear gel with 6 ppg 20/40 mesh sand, 60 and 40 lb/Mgal hydroxypropyl guar (HPG) linear gels both with 4 ppg 20/40 mesh sand, and borate-crosslinked 35 lb/Mgal guar gel with 7.3 ppg 20/40 mesh sand. Test conditions cover a shear rate range of 60 to 120 sec−1. In addition, the effect of an enzyme breaker on proppant settling rate under static conditions was studied. Tests were conducted with a fracture gap width of 0.375 in. under ambient conditions.
Analysis of the dynamic condition indicates that proppant settling within the linear and crosslinked gels investigated is non-linearly dependent on shear rate. Under static conditions, linear gel slurries settled 40 to 50 times faster than the crosslinked gel containing breaker. It is also shown that an increase in shear rate induces proppant settling in borate-crosslinked 35 lb/Mgal guar gel while it reduces the settling rate in 35 lb/Mgal guar linear gel.
Use of Soil Venting for Remediation of Condensate Contaminated Soils
Authors: Wittenbach Stuart , Lower Steve , Biagi Chris 
Published: December 2007

Abstract
Although the oil and gas industry has a good environmental spill record, sometimes a spill of condensate occurs on oil and gas leases, flowlines/pipelines, gas plants and other sites. Due to the different characteristics of condensate, when compared to crude oil, the remediation of these spill sites varies. Many of the typical options in use today are soil removal, soil venting, soil farming, bioremediation, and thermal-desorption. The challenge for the environmental and operations managers is to select the best system for the each particular site.
Costs and liability for off-site disposal and potential groundwater contamination are ever increasing. Kerr-McGee conducted a study of passive and mechanized soil venting of condensate contaminated soils in the panhandle area of Texas. Both systems proved to be practical and effective.
Goals of the project were to: Remediate the contaminated soils to the Railroad Commission of Texas limits.Determine the effectiveness of both systems.Remove the possibility of any groundwater contamination by remediation of the soil profile.
All three goals were met and this paper summarizes the results of this project and provides another tool for remediating condensate-contaminated soils.
New Tricks for an Old Tool: A Case Study of an Unconventional Use of Temperature Logging
Authors: Robin George J. , Pontoriero Pat 
Published: December 2007

Abstract
The plugging and abandonment (P&A) of a Class 1 Hazardous injection well (previously a Class II, oil and gas well) in California was dependent upon satisfying state and federal requirements, which included placement of cement plugs inside the casing and, if needed, in the annular space between the casing and the original drilled hole. Pressure which had built up inside the annular space between the tubing and casing during the ten year shut-in period was suspected to be caused by a very small casing leak. The concerns regarding the unconfirmed existence and unknown location of this suspected leak in the casing made the P&A Plan more complicated and potentially more expensive to account for all the possible scenarios that could occur. The U.S.E.P.A. required that the P&A Plan include locating the cause of the casing pressure and either remediating the leak or preventing any future harmful effects to the environment. Since a temperature tool would be utilized to establish External Mechanical Integrity in the well, it was decided that the same tool could possibly be used to locate the casing leak. The development of these "alternate" procedures were based upon the principles of the temperature tool's ease of operation, its sensitivity and resolution, and its reliability. The temperature tool was used to reflect a disturbance of fluids in the tubing/casing annulus that were previously stable. This paper discusses those procedures, the results and conclusions of that portion of the P&A operation, and the rig time cost savings from conventional methods.
Innovative Regulatory Approach for Synthetic-Based Drilling Fluids
Authors: Veil J. A. , Daly J. M. 
Published: December 2007

Abstract
The oil and gas industry has historically used water-based muds (WBMs) and oil-based muds (OBMs) in offshore drilling operations. WBMs are less expensive and are widely used. Both the WBMs and the associated drill cuttings may be discharged from the platform to the sea provided that U.S. Environmental Protection Agency (EPA) discharge limitations are met. In some wells, however, difficult drilling conditions may force a switch from a WBM to an OBM. Neither the OBM nor the associated drill cuttings may be discharged. The OBM is hauled to shore, where it is processed for reuse, while the associated cuttings are injected in a disposal well at the platform or hauled to shore to a disposal facility. Both of these options are expensive. Synthetic-based muds (SBMs) are drilling fluids that use synthetic organic chemicals as base fluids. SBMs were developed to replace OBMs in difficult drilling situations. SBMs are more expensive than OBMs; however, they have superior environmental properties that may permit the cuttings to be discharged on-site. Like OBMs, SBMs are hauled ashore for processing and reuse after the well is drilled.
The existing national effluent limitations guidelines (ELGs) for the offshore industry do not include requirements for SBM-cuttings since SBMs were not commonly in use at the time the ELGs were adopted. In late 1997, EPA announced that it would modify the offshore ELGs to include requirements for discharges of cuttings drilled with SBMs. For the first time in the history of the ELG program, EPA is following an innovative expedited rulemaking process that will lead to development of draft regulations in one year rather than the 4- to 6- year period usually needed. With direction from the federal government to stakeholders concerning information needs for the regulatory development, the industry has established sev eral working groups to collect new scientific information on SBMs. This paper describes the expedited rulemaking process and summarizes the findings of the workgroups to date.
Using Remote Sensing for Environmental Baseline Studies
Authors: Henderson Douglas R. 
Published: December 2007

Abstract
Remote sensing is a powerful tool for environmental baseline studies related to oil and gas operations. Oil and gas lease blocks are frequently too large, or their terrain too difficult, to study and map from the ground in a timely, cost-effective manner. The use of remotely sensed imagery allows for rapid, inexpensive analyses. This paper reviews the basics of remote sensing technology while highlighting innovative examples of environmental projects concerning oil and gas exploration and production sites that successfully used remotely sensed data. Case studies presented span a range of approaches covering regions in Peru, Ecuador, and California. Several of these projects used remote sensing in challenging rainforest environments.
A variety of technologies—panchromatic and multispectral satellite images, aerial photography, radar data, and GPS—are employed to address different environmental assessment needs. Such needs often include assessments of lease blocks during ownership transfer, or periodic environmental monitoring of discharge zones, pipelines, well pads, and associated infrastructure. Remotely sensed data can also provide the backbone for environmental impact assessments and change detection studies.