bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of True Hook Load and Line Tension Under Dynamic Conditions
Authors: Luke G. R. , Juvkam-Wold H. C. 
Published: December 2007

SummaryTheoretical and experimental studies show that true hook load depends on sheave friction, direction of block movement, and previous movement history. In some cases, actual hook load was observed to be up to 19% higher than the load predicted by the method currently used in the oil industry.
The Influence of Chemical Potential on Wellbore Stability
Authors: Hale A. H. , Mody F. K. , Salisbury D. P. 
Published: December 2007

Summary
An experimental investigation was begun to understand fundamental borehole stability mechanisms. This laboratory study was directed toward understanding why and how drilling-fluid chemistry affects borehole stability. The ability of drilling-fluid chemistry to alter shale mechanical behavior and the borehole stress state as a result of shale water content alteration was investigated. Experimental results demonstrate the influence of various drilling-fluid parameters (e.g., salt concentration, salt type, and diesel/water ratio) in oil-based drilling fluids on the water content, compressive strength, and mechanical properties of five shales. The influences of temperature and drilling-fluid exposure time on shale strength alteration also are addressed. The results are explained on the basis of chemical potential differences between oil-based drilling fluid and shale. The change in the shale water content caused by these differences is identified as the predominant factor leading to alteration of shale mechanical behavior and hence borehole stability.
A Simple Approach to Optimization of Completion Interval in Oil/Water Coning Systems
Authors: Boyun Guo , Lee R. L -H. 
Published: December 2007

Summary
An analytical solution is presented to estimate the maximum water-free production rate (critical oil rate) that considers the effect of limited wellbore penetration on the oil productivity of the well. To maximize the critical oil rate, an optimum wellbore penetration into an oil zone is determined theoretically. This analytical solution shows that the optimum wellbore penetration into a pay zone is less than one-third the total pay-zone thickness.
New Coiled-Tubing Cementing Techniques at Prudhoe Developed To Withstand Higher Differential Pressure
Authors: Krause R. E. , Reem D. C. 
Published: December 2007

Summary
The successful hydraulic fracturing program at Prudhoe Bay would not have been possible without an effective coiled-tubing-unit (CTU) cement-squeeze program. Many fracture stimulation candidates were wells that had been squeezed previously. Therefore, squeezed perforations were exposed to higher differential pressures during fracturing operations than normally were seen at Prudhoe. At the outset of the fracture stimulation program in 1990, squeeze perforations failed when subjected to fracture job pressures. It quickly became clear that more aggressive CTU squeeze techniques resulting in stronger squeezed perforations would be necessary if the Prudhoe fracture program were to achieve its goals. Arco Alaska Inc. implemented a more aggressive CTU squeeze program in the Eastern Operating Area (EOA) in mid-1990. This paper documents the results of the new squeeze program, in which increased surface coiled-tubing squeeze pressures from 1, 500 to 3, 500 psi for 1 hour were used. More resilient, acid-resistant latex cement also became the standard in late 1990 for squeeze cementing. Implementation of this program has resulted in a squeeze success rate approaching 90%.
Redesigned Ester Single-Well Tracer Test That Incorporates pH-Driven Hydrolysis Rate Changes
Authors: Wellington S. L. , Richardson E. A. 
Published: December 2007

Summary
The rate of alkyl ester hydrolysis was found to be sensitive to the pH changes that occurred during application of the single-well tracer test (SWTT) in both sandstone and turbidite reservoirs. Detection methods, an improved test sequence, and the detrimental consequences that this variable can have on oil saturation determination are discussed.
Some Pulsed Neutron Logging Contributions To Improved Formation Evaluation
Authors: Fons Lloyd 
Published: December 2007

Pulsed neutron logging, because it can be performed in cased wells, is supplying previously unobtainable information for evaluating reservoirs. When spaced in time, these logs make it possible to deduce the nature of water encroachment and hydrocarbon depletion at any stage in the producing life of a well.

Introduction
Hydrocarbon volume and geometry within a reservoir must be determined before the efficiency of hydrocarbon production can be judged. This requires a more thorough analysis than is possible during the early development of a field. During this early period many assumptions (universally based on incomplete sampling) are made for a number of factors including water saturation, reservoir boundaries, average reservoir thickness and ultimate recovery efficiency. Data obtained by initial drilling, well logging and production tests are the primary tools for early evaluation of the reservoir. Production history is inadequate in the initial stages of pool development, but as a field is developed and more wells are logged, more data are collected, and useful production history accumulates. The production trends may change depending upon rate of production, drive mechanism, state of reservoir development, porosity and permeability distribution, and efficiency of completion methods. All in all, production history is regulated by a complex set of conditions, some of which have been rather arbitrarily established by the engineer.
It is commonly assumed that the formations exposed by the wellbore of the discovery well are representative of the subsurface of the entire location (or lease). Each log of a subsequent well will measure the physical properties of the formations immediately surrounding that particular well. The formations exposed are generally thought to extend laterally and continuously to connect with counterparts in adjacent wells. Preferential watering-out of individual strata within a formation commonly occurs.

Pulsed Neutron Logging
Pulsed neutron logging (PNL) has been well described in the literature.1-6 It is relatively insensitive to commonly occurring changes in borehole size and fluid type,7 and is well suited for use in cased wells. The casing of a well before "open-hole" logs are run no longer precludes the high probability of efficient formation (and well) evaluation by logging methods. The resulting cased-hole logs, when used with companion services such as neutron or interval-time logging through casing, will supply much the same information as is obtained from standard open-hole logging programs.
New Chemistry for the Placement of Chromium(III)/Polymer Gels in High-Temperature Reservoirs
Authors: Lockhart Thomas P. , Albonico Paola 
Published: December 2007

SummaryCoordination chemistry concepts have been used in the development of Cr+3/polymer solutions that meet the delayed-gelation requirements for in-depth treatment of high-temperature reservoirs. Use of the malonate complex of Cr+3, Cr(malonate)3)3, provides gelation delays at elevated temperature much greater than those obtained with either the hydrated Cr+3 ion or Cr(acetate)3. Inclusion of additional, uncomplexed malonate ions in the formulations provides a means for further, and predictable, extension of the gelation time. The gelation delays obtained over the temperature range of 90 to 135 °C are equal to or greater than those that can be achieved with the best gelation delay technologies described previously.The dependence of the gelation time on temperature, pH, and the Cr+3 and malonate ion concentrations has been investigated. Preliminary results indicate that the thermal decomposition of the delaying ligand, malonate, plays an important role in determining the gelation rate. The use of a Cr+3 complex of relatively low toxicity rather than the carcinogenic Cr+6 ion to control gelation rate is an amctive feature of the new technology.
Reservoir Barrier and Polymer Waterflood, Northeast Hallsville Crane Unit
Authors: Moore Joe K. 
Published: December 2007

As a result of field-wide polymer injection, recovery in this unit exceeded by 40 percent the estimated recovery for an ordinary waterflood, and at an average cost of just 33 cents per barrel.

Introduction
The Northeast Hallsville Crane unit operated by Hunt Oil Co. was one of the first field-wide applications of a polymer flood. Since this field is well along in the final stages of be flood project, it has been possible to look at the effects of polymer injection and draw some conclusions about the use of these chemicals. The original purpose of polymer use in this project was to create a viscous barrier between the oil zone and a large associated gas cap. However, flood response from nearby producers as a result of the barrier placement was encouraging enough to extend the use of polymers to the central area of the oil zone, where early water breakthrough had been experienced. Early results from these attempts at using polymers to improve waterflood recovery were favorable. Ultimately a total of 313,000 lb of polymer was injected into 10 of the 15 unit injectors. Polymer injection into the Northeast Hallsville Crane unit generally has been both technically and economically successful. Certainly, the effectiveness of the reservoir barrier has been well established. As for improvement of oil recoveries by mobility control, it was found that higher polymer amounts resulted in higher oil recoveries over the range of polymer treatments used. Substantially better results were achieved in areas where there was no water injection prior to the polymer slug injection. prior to the polymer slug injection. Development History
The Northeast Hallsville Crane unit is about 3 miles northwest of the town of Marshall in Harrison County, Tex. Unit production is from the Crane zone of the middle Pettit formation, a thin oolitic limestone pay at a depth of about 6,900 ft. The map in Fig. 1 pay at a depth of about 6,900 ft. The map in Fig. 1 shows the location and areal extent of the Crane porosity development and its relation to the large porosity development and its relation to the large associated Woodlawn gas field. The Crane pay in this area was first discovered in 1950 as a gas producing reservoir in the Woodlawn portion of the field. Oil production was established portion of the field. Oil production was established in the Northeast Hallsville field in 1956 as the reservoir was developed to the west. Reservoir lists had been essentially defined by early 1960 after 42 wells had been drilled. Primary oil production peaked in March, 1959, at 42,500 bbl/month. Early withdrawals from the gas zone had caused migration of oil into the gas cap by the time of the oil zone development. As a result, the gas-oil contact was not found as a clearly defined structural level but was established as a broad transition zone between approximately 6,300 and 6,400 ft subsea. The extreme volatility of the crude oil also contributed to the lack of a clearly defined gas-oil contact.
JPT
P. 1130
Development and Application of a Knowledge-Based Expert System for Cement Slurry Design
Authors: Kulakofsky D. S. , Wu F-L. , Onan D. D. , Wohleb J. B. 
Published: December 2007

Summary
Traditionally, quality oilfield cement slurries have been based on rules of thumb and years of experience. The designs used in specific areas often were developed many years ago. Although these slurries may have used the best technology available when they were designed, these designs often can be improved with newer technology and products. A knowledge-based expert system can provide information regarding the latest products and technology, as well as the knowledge necessary to use them properly. This paper discusses the expert slurry-design system (ESDS) and the various considerations involved in developing a useful and usable expert system. This discussion covers establishing system goals and requirements, developing the knowledge base, creating the user interface, operating the system, and confirming ESDS results.
OILWAT - Microcomputer Program for Oil Material Balance With Gas Cap and Water Influx
Authors: Wang Ben , Litvak B. L. , Bowman G. W. 
Published: December 2007

Summary
This paper describes an interactive computer program, OILWAT, for material-balance calculations in oil reservoirs with gas cap and water influx. A material-balance calculation uses production and pressure data to calculate original oil in place (OOIP) and aquifer characteristics. This formulation can be very useful in a history match to define reservoir and aquifer parameters before a simulation study. It also can be used to predict future pressure and primary production.
The use of different material-balance methods usually results in different OOIP estimates. OILWAT helps solve this problem by combining several material-balance methods with various aquifer options (small pot, steady state, and unsteady state) and comparing them statistically. Panel input and graphical output are available in the program.
Several important features are (1) variable bubblepoint, which enables very good history match during repressuring of the depleted reservoirs; (2) variable rock compressibility for abnormally pressured reservoirs; (3) an option to calculate original gas-cap or aquifer size provided that OOIP is known; and (4) applicability to saturated and/or undersaturated reservoirs. In contrast to most material-balance programs, OILWAT permits the use of a single data set for a reservoir initially at undersaturated condition that subsequently drops below bubblepoint.
A Multiplatform Reservoir Engineering Support System
Authors: Middlebrooks C. H. , Stephenson R. E. , Beard S. L. , Cummings D. L. , Hill R. L. , Natowsky P. F. , Burstall F. C. 
Published: December 2007

Summary
The UNIX Reservoir Engineering Support System (RESS) is a system of networked computer applications delivering cost-effective access to state-of-the-art technology for reservoir evaluation and forecasting. This reservoir simulation support system is a set of tools to enhance engineering productivity for efficiently managing the exploitation of oil and gas reserves. RESS provides a dynamic environment in which multiple reservoir engineering tasks, such as data preparation, reservoir model submission with subsequent monitoring, and graphics, can be processed and displayed simultaneously. RESS integrates applications with complex interfaces over UNIX networks with X Window client/server architecture. The powerful multiplatform computing environment includes tools for various reservoir engineering applications residing on various platforms and the accessibility to all of it from the computing platforms on engineers' desks.
Quality Improvement: What Does It Mean in an Exploration and Production Environment?
Authors: Erickson Ron 
Published: December 2007

Distinguished Author Series articles are general, descriptive representations that summarize the state of the art in an area of technology by describing recent developments for readers who are not specialists in the topics discussed. Written by individuals recognized as experts in the area, these articles provide key references to more definitive work and present specific details only to illustrate the technology. Purpose: to inform the general readership of recent advances in various areas of petroleum engineering.

Summary
The implementation of quality improvement in E&P is a fairly new idea. Many questions exist about how quality improvement can work in E&P. This paper addresses some of the most fundamental quality improvement issues. What is quality in E&P? How can quality be measured in E&P? How can quality be improved in E&P? What are the benefits of quality improvement?

Introduction
In the mid-1970's, great underlying changes, like shifting tectonic plates, began to occur in world economics. At first, they were unnoticed by most industries. But slowly and steadily, the U.S. began to lose its previously unmatched, unchallenged, and unquestioned leadership to a country that was in postwar ruin 30 years before. As a new economic age emerged, quality became a key business strategy-one that Japanese companies have used to dominate many industries.
Without a foundation built on total quality, industries were vulnerable. Within a few short years, economic quakes damaged several U.S. industries, and others vanished.
Ironically, during the 1970's and 1980's, quality actually increased in many U.S. industries. But advances in U.S. product quality could not keep up with international quality improvement. U.S. quality improved at an evolutionary rate, while Japanese quality improved at a revolutionary rate. As U.S. consumers experienced higher quality in non-U.S. products, their expectations and requirements rose faster than U.S. companies could adapt.
How Did It Happen?
The story begins 100 years ago. In the early 1900's, a scientist at Bell Laboratories noticed that successful scientists follow a general pattern to improve scientific knowledge with new ideas. First, they plan a way to test their ideas through experimentation. Second, they do their experiments. Third, they check the measured results against the planned results. Fourth, they act on the results. If their ideas are not verified, or not verified completely, they start over by modifying their ideas. But, if their ideas are validated, these ideas become standardized and are added to the body of scientific knowledge. Then, successful scientists start the process over with other ideas. The scientist who described this plan/do/check/act process of continuous experimentation was Walter Shewhart.
Applying Fractional-Flow Theory to Foams for Diversion in Matrix Acidization
Authors: Zhou Z. H. , Rossen W. R. 
Published: December 2007

SummaryFractional-flow analysis based on foam-coreflood data and the "limiting-capillary-pressure" model presents a simple, approximate way to predict diversion in foam matrix acidization. Preliminary results show that the greatest diversion is obtained when foam is preceded by a surfactant preflush and is followed by an acid slug compatible with foam.
Advances in Computer-Aided Well Test Interpretation
Authors: Horne R.N. 
Published: December 2007

Summary
Several different computer methods combine to constitute a computer-aided well-test interpretation. This paper compares some of the different approaches currently in use. Future directions are discussed, as are deconvolution, pressure derivatives, model recognition, nonlinear regression, and confidence intervals.

Introduction
Despite the feeling expressed several times over the past 40 years that well-test analysis had reached its peak development, an examination of recent advances shows continuous expansion in capability, with future improvement likely. The expansion in interpretation capability over the past decade arose mainly from the development of computer-aided techniques, which, although introduced 20 years ago, have come into use only recently. The broad application of computer-aided interpretation originated with the improvement of the methodologies and continued with the expansion in computer access and capability that accompanied the explosive development of the microcomputer industry.
This paper focuses on the different pieces of the methodology that combine to constitute a computer-aided interpretation and attempts to compare some of the approaches currently used. Future directions of the approach are also discussed. The separate areas discussed are deconvolution, pressure derivatives, model recognition, nonlinear regression, and confidence intervals.

Background
During the 1970's and 1980's, mathematical and numerical techniques provided new well-test solutions for a wide variety of reservoir configurations, such as fractures, layered reservoirs, and multiple porosities. The complexity of these models and the large number of parameters that they contain limited their analysis by traditional graphical methods. Of the two main types of graphical analyses, straight-line methods (such as Horner plots) can provide estimates of, at most, two unknowns (from the slope and intercept of the line). Type-curve methods can usually provide only three parameters--one from each of the two axes and one from a curve from the family of curves used. In the process of seeking a method to match more unknowns, work began on the use of nonlinear regression. Earlougher and Kersch's 1972 paper was key in this area. That and later work showed that nonlinear regression could not only match reservoir models with more than a few parameters, but also provide several significant advantages over graphical matching. One important advantage was the illustration of the use of confidence intervals, another was the application of nonlinear regression to reservoir responses that resulted from complex (variable-rate) impulses. Matching complex models and complex impulses made up the challenge in and motivation for computer-aided analysis.
Validation of Coiled-Tubing Penetration Predictions in Horizontal Wells
Authors: van Adrichem Willem , Newman K.R. 
Published: December 2007

Summary
This paper compares the predictions of a coiled-tubing tubing-forces model (TFM) with actual measured data from more than 20 wells. The model predicts the maximum depth of penetration that the coiled tubing will be able to achieve before "helical lockup" is reached and predicts the weight indicator reading as the coiled tubing is pushed through the horizontal section to lockup. The predicted penetration depth and the weight indicator readings are compared with actual values recorded during the job for open- and cased-hole completions.

Introduction
Coiled tubing is being used increasingly to service highly deviated (including horizontal) wells as the number of these wells increases. Services typically performed with either electric line or slick line in horizontal wells are often performed with coiled tubing because the coiled tubing is rigid and can be pushed into the highly deviated section of the well. Services typically performed with drillpipe or conventional tubing often are performed with coiled tubing to avoid rig costs. The services currently being run in highly deviated wells include logging, perforating, setting and retrieving plugs, opening and closing sliding sleeves, fishing, removing fill, drilling, and matrix acidizing and acid washing.
Several questions need to be answered when a coiled-tubing operation in a highly deviated well is designed. These questions include the following.How far can the coiled tubing safely penetrate and push tools into the deviated section?How can the operator ensure that the coiled tubing is being pushed into and not becoming bent in the well?How much weight can be applied with the coiled tubing to a drill bit or any other downhole tool at a point in the deviated section?
To answer these questions, a TFM was developed specifically for coiled tubing. This paper describes this model, which has been validated with measured data from jobs performed in highly deviated wells.