bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cementing Temperature Predictions Based on Both Downhole Measurements and Computer Predictions: A Case History
Authors: Honore R. S. , Tarr B. A. , Howard J. A. , Lang N. K. 
Published: December 2007

SUMMARY
To plan the cementing operations in a deep, high temperature well drilled in the Rocky Mountains, accurate circulating temperatures were required. Temperature measurements made while drilling were used to validate a computer predicted drilling temperature profile. Given the hole geometry, the geometry of the string to be cemented, the planned cementing fluids, and the planned pumping rates the computer model was used to predict the circulating temperatures while cementing. These predicted temperatures were then used to optimize the cement slurry design.
In-Situ Upgrading of Heavy Oils and Bitumen by Propane Deasphalting: The Vapex Process
Authors: Mokrys I. J. , Butler R. M. 
Published: December 2007

Abstract
Many of the Lloydminster-type heavy oil reservoirs are unsuitable for thermal recovery by steam injection because they are relatively thin and the heat losses to the under- and overburden are excessive. To overcome this difficulty, a new approach has been proposed which utilizes the injection of saturated hydrocarbon vapours at approximately reservoir temperature. There are several modifications of the basic principle under development in which the amount of extraneous heat injected varies from none to moderate, and the vapour chamber is maintained at reservoir temperature to 30°C above it. This flexibility allows the approach to be followed for the recovery of both conventional heavy oils and for bitumen.
The method, termed "Vapex", utilizes two horizontal wells and is closely related to the SAGD process but with the steam chamber replaced by a chamber containing hydrocarbon vapour near its dew point.
The quality of bitumen or heavy oil can be improved substantially by in situ deasphalting with propane vapour. The removal of asphaltenes reduces the viscosity of the produced oil and creates an oil that is more easily refined.
In this paper we present new experimental results obtained in a scaled physical laboratory model and discuss the effect of factors such as injected G/O ratio, different saturation pressures and vapour chamber temperatures on the rate of oil production, the extent of in situ deasphalting and the quality of the recovered oil.
Production Performance of Hydraulically Fractured Gas Wells
Authors: Liao Yizhu , Lee W. J. 
Published: December 2007

ABSTRACT
This study presents simulation results of fracture fluid cleanup and gas production behavior for hydraulically fractured gas wells. Isotropic and anisotropic, and single- and multi-layer reservoirs were studied. Systematic investigation revealed that formation damage near the fracture is a key factor affecting fracture fluid cleanup and gas production. Also, improper simplification of a multilayer reservoir may lead to overestimates of gas production.
An Integrated Laboratory and Field Study to Optimize the Hydraulic Fracturing Fluid System in a High-Permeability Reservoir
Authors: Keck R. G. , Hainey B. W. , Clausen R. A. 
Published: December 2007

Abstract
This paper presents results of an extensive laboratory and field program to optimize the fracturing fluid system used in the ARCO-operated Eastern Operating Area of the Prudhoe Bay Unit on the north slope of Alaska. This study focuses on the fracturing fluid rheology, fluid loss additives and retained proppant conductivity for this high permeability fracturing application. Results of 60 static fluid loss tests performed on filter paper led to optimization of degradable starch loadings and identification of 5% diesel as an effective fluid loss additive. Subsequent dynamic fluid loss tests on Prudhoe core discounted benefit of the diesel, but proppant conductivity testing showed the diesel did improve proppant pack clean-up. Results of mini-fracs performed showed diesel provided identical performance to the significantly more costly degradable starch additive. Laboratory tests of fluid rheology found that orders-of-magnitude increases in viscosity could be obtained by increasing the pH of the delayed-borate crosslinked guar systems used for the 200°F BHT. Despite recent changes in strategy due to smaller treatment sizes (as described by Martins et al1), the results of these laboratory tests have been used to dramatically lower fluid loss additive costs and improve fluid system performance in the high permeability Prudhoe fracturing program.
A Simple Algorithm for Analyzing Gas Pipeline Networks
Authors: Tian Shifeng , Adewumi M. A. 
Published: December 2007

Abstract
A novel algorithm is developed for analyzing and designing gas pipeline networks. The step-forward algorithm is very simple in that it does not require the use of matrix algebra as most existing algorithms do. The simplicity of the method is evidenced by the fact that smaller-sized pipeline networks can be analyzed with a programmable calculator. At the same time, the algorithm provides the means for analysis of any type of steady state gas network. The required input data structure is also quite simple in that no flow direction pre-assignment is necessary. In this work, guidelines are developed to enable the user to determine the minimum data required for analyzing a particular system and to help the user define a well-posed problem.
Naturally Fractured or Single-Porosity? The Importance of Reservoir Flow Model for Performance Assessment of Stimulated Tight Gas Wells
Authors: Carlson E. S. , Latham G. V. 
Published: December 2007

ABSTRACT
We present here the first practical application of a discrete fracture network model, a new type of model for naturally fractured reservoirs. We show how the behavior of fractured reservoirs differs from single-porosity reservoirs, and give the results of several sample calculations. These examples clearly illustrate that the reservoir-flow model must be considered when evaluating flow improvements resulting from well stimulations.
Simulation of Skin Effects and Liquid Cleanup in Hydraulically Fractured Wells
Authors: Iqbal G. M. , Civan Faruk 
Published: December 2007

ABSTRACT
An integrated model is developed to study the skin damage and liquid cleanup of hydraulically fractured wells during post-fracture production. The adverse effects of an injected liquid phase present in the invaded region adjacent to the fracture are simulated by the two-phase and threedimensional flow equations for gas and water in formation, fracture and damaged zone. A phenomenological model simulating the effects of clay swelling and migration of fines leading to skin in the liquid invaded region is incorporated in the study.
Simulation of liquid cleanup is accomplished by first considering the injection of fracturing fluid to study the extent of invaded region and the degree of permeability reduction. This is followed by simulation of liquid recovery and gas production under altered reservoir conditions.
It is found that the mathematical modeling of fluid injection and subsequent cleanup requires formulation of non-linear and coupled model equations, prudent numerical schemes, implementation of refined grids and curvilinear coordinates, and versatile solution methods. The model has been applied to typical field cases, and simulation results indicate that factors such as permeability alteration in the damaged zone and gas relative permeability in presence of a liquid phase must be considered in designing a successful hydraulic fracturing operation.
The Chemistry Prediction and Treatment of Scale Containing Naturally Occurring Radioactive Materials (NORM) in Antrim Gas Fields, Michigan
Authors: Oddo J. E. , Al-Borno Amal , Ortiz Isais , Anthony Robin , Pope D. H. , Hill D. G. , Linz D. G. , Frank James , Becker D. M. , Tomson M. B. 
Published: December 2007

Summary
BaSO4 scale containing Naturally Occurring Radioactive Material (NORM) as well as calcium carbonate scale has been reported in gas production facilities in conjunction with the Antrim play in northern Michigan. The scale study was undertaken by the Water Research Institute, Inc. (WRI) under contract from the Gas Research Institute. It was proposed in the scale study to conduct a two phase systematic characterization of BaSO4 scale from the Michigan Basin area both as to occurrence and environmental hazard, and to evaluate scale control methods using brines typical of the area. The initial study involved sample collection and analytical work-up to arrive at a correct theoretical analysis of the problems involved. The variability of the sulfate concentrations in the wells is addressed and scale prediction techniques applied to the reservoirs and the surface equipment to determine where scale was forming and where it is likely to form. The scale is proposed to be forming due to the commingling of produced waters from wells with high sulfate concentrations with waters from other wells relatively high barium concentrations. Inhibitor evaluations were done using a high temperature-pressure laboratory apparatus developed at Rice University and WRI (patent application pending with GRI) and effective chemicals and probable dose rates for inhibition were determined. Concurrently, studies were begun by Bioindustrial Technology, Inc. and United Exploration and Development Consultants to learn the sources of the high sulfate concentrations reported in some wells in the area and to determine the causes of souring in some others.
In addition to the scale forming in the surface facilities, NORM scale was predicted and found in production tubing from individual wells. The driving forces for scale precipitation in these wells is the temperature and pressure changes resulting from production Chemical squeeze of inhibitor into the reservoirs and surface injection are recommended to treat and eliminate the scale problem.
An Improved Method for Measuring Fracturing Gel Break with Resin-Coated Proppant
Authors: Harris P. C. 
Published: December 2007

Abstract
Significant gel break problems may exist when using borate crosslinked fluids with resin coated proppants (RCP). A test method was developed which measures proppant settling, fluid breakdown, and flow of broken fluid through the settled proppant pack. Generally, sand settling was nearly complete before the fluid showed significant signs of breaking. The degree of break was determined by measuring the rheological character of broken fluid flow in the proppant pack. This measurement discriminated whether the fluid was fully broken to water-thin or retained base gel character, and whether the proppant pack was partially plugged by broken gel residue.
Guar and HPG borate crosslinked fluids were examined with different breakers, including delayed release oxidizers, enzymes, and acids. Effects of uncoated proppants and resin coated proppants were tested. The dynamics of breaking borate fluids containing curable RCP, which release oxidizer consuming materials, suggests that the release of breaker chemicals must occur at the proper sequence for the polymer breakdown process to work.
The method presented in this paper is useful for observing the process which occurs after a fracturing process is pumped, i.e., proppant settling, fluid breakdown, and flow of fluid through a proppant pack. Concentrations of breaker materials for crosslinked fluids can be determined in the presence of RCP.
Acid Inhibition for Coiled Tubing: Laboratory Screening and Field Verification
Authors: Blount C. G. , Herring G. D. , Patterson W. W. , Walker M. L. 
Published: December 2007

ABSTRACT
Questions concerning acid inhibitor effectiveness at high velocities and in the oxygen rich environments common to Coiled Tubing (CT) applications prompted laboratory testing of several acid inhibitors at various concentrations in common acid stimulation fluids.
Following the laboratory testing, special CT nozzles were manufactured to position standard corrosion coupons in the direct path of the stimulation fluid flow as it exited the CT during acid treatments. The data gathered from the corrosion coupons were used to validate the laboratory tests.
As a result of these studies, unnecessarily high acid inhibitor volumes and undesirable or even potentially hazardous field practices were discontinued. The information learned from the studies was incorporated into field practices, which resulted in safer, lower risk operations, reduced the chance of formation damage, and lowered the overall operating costs for acid stimulation treatments.
This paper documents the testing and results of the lab and field studies. In addition, the nozzles described in this paper provide an easily implemented and inexpensive quality control tool for CT acid work in virtually any area CT stimulations are performed.
Study of Helical Buckling of Pipes in Horizontal Wells
Authors: Wu Jiang , Juvkam-Wold H. C. 
Published: December 2007

ABSTRACT
This paper studies helical buckling, and also critical (sinusoidal) buckling, of pipes (tubing and drillstring) in horizontal wells. The large frictional drag of helically buckled pipes is also studied.
Helical buckling is developed from critical (sinusoidal) buckling as the axial load keeps increasing. But fully developed helical buckling of pipes will not occur in horizontal wellbores until the axial load becomes very large, about 1.8 times the critical buckling load that predicts the onset of sinusoidal buckling, and about 1.3 times the so-called helical buckling load that appears in the current literature. The so-called helical buckling load in the current literature is actually the average axial load in the helical buckling development process. This means larger bit weight or tubing packer load may be applied to increase the drilling rate or to ensure a proper seal, before helical buckling of the pipes can occur.
However, once fully developed helical buckling occurs, the frictional drag may become much larger than it was before the onset of helical buckling. The pipe could even become "locked-up" so that the bit weight or packer setting load can not be increased any more by slacking off weight at the surface.
Analyzing Old Electric Logs in Shaly Sand Formations
Authors: Walsh J. W. , Brown S. L. , Asquith G. B. 
Published: December 2007

Abstract
Analyzing shaly sand formations is complicated even with modem logging suites accompanied with core or CEC data. However when only older logs are available the analysis must be made with fewer models and comparative calculations. This paper outlines several methods for analyzing older electric logs including: computing effective porosity computed from resistivity curves, computing water saturation using the No Porosity Automatic Compensation Model (Asquith, 1990), and Dual Water No Porosity Model (Elphick, 1988), using statistical crossplots, and correlating GR and SP curves to curves from new wells having Cation Exchange Capacity data to utilize the Waxman-Smits Method for estimating water saturation. Examples from two wells are presented to illustrate a procedure for obtaining reliable results from old electric logs.
Integrating Wireline Data With Three-Dimensional Hydraulic Fracture Simulators in the Spraberry Trend
Authors: Barba R. E. , Meyer B. R. 
Published: December 2007

Abstract
Two-dimensional hydraulic fracture simulators are used to design the majority of hydraulic fracture treatments in West Texas. These models assume a fixed hydraulic fracture height. In many cases, hydraulic fracture treatments often do not stay confined within a fixed height as the two dimensional models assume. In the Spraberry/Dean siltstones of West Texas there are no strong barriers to vertical fracture migration, and two dimensional models are clearly inappropriate. Three dimensional hydraulic fracturing simulators overcome this limitation of a fixed height by calculating the fracture height. The inputs required are considerably more involved, and the 3D models require data from both the pay sands and boundary layers. If the raw input data are not available or if sufficient engineering effort is not invested the model output may be misleading. Wireline logs can provide valuable inputs to these three dimensional simulators. These inputs will be discussed, along with case studies where the inputs helped optimize the completion design.
Proven Logging Technology for High-Bottomhole Temperatures
Authors: Gonzalez M. E. , Archuleta J. R. , Polly R. E. 
Published: December 2007

ABSTRACT
This paper describes how a commonly encountered problem with logging deep, hot holes throughout the United States was overcome through the cooperation of a major oil company, service company, and national laboratory. First, we review the past, unreliable performance of standard industry tools during long logging runs at high bottom hole temperatures through actual field examples. Next, we discuss the innovative tool redesign that keeps the inside of the tool cool without increasing the outside diameter of the tool. Finally, we present a comparison of the hot hole and standard tool operating performance in both the laboratory and numerous field examples.
Integrated Field Development Planning Using Risk and Decision Analysis to Minimise the Impact of Reservoir and other Uncertainties: A Case Study
Authors: Stripe J. A. , Arisaka Kazuyoshi , Durandeau Marc 
Published: December 2007

ABSTRACT
The development strategy for a new field is based on the data available from seismic surveys and exploration and appraisal wells. Limitations in this information may still leave large uncertainties in field performance predictions leading to a low confidence in ranking of reservoir recovery methods. Typical development planning based upon single point deterministic reservoir modeling may not be sufficiently flexible to cover all possible outcomes in an optimum manner. This problem may be largely overcome by adopting a more geostatistical approach in which the data uncertainties are reflected within probability distributions for relevant reservoir parameters.
In addition to reservoir uncertainties the importance of fully integrating drilling, surface facilities, and economic constraints is sometimes not obvious during the initial reservoir screening exercise. The ranking of reservoir recovery methods and related development strategies may be radically altered by imposition of these constraints.
Analysis of key decision points and the risks associated with them may be utilised to assist in the formulation of field development strategies that minimise the impact of uncertainties in the limited data. Many strategies may be tested and levels of associated risk and value quantified. Measures to reduce unacceptable risks may be specified. Ultimately an optimal development strategy may be selected.
This paper describes application of the above considerations within an integrated development planning study carried out for an undeveloped field offshore Abu Dhabi.
A Comparison of Existing Multiphase Flow Methods for the Calculation of Pressure Drop in Vertical Wells
Authors: Espanol J.H. , Holmes C.S. , Brown K.E. 
Published: December 2007

Abstract
The estimation of pressure drop for multiphase flow in a vertical pipe is one of the more complex problems in oil field practice. The most successful solutions to this problem involve trial and error calculations in problem involve trial and error calculations in subdivided sections of flow patterns. No two methods yield identical results for a given set of flow conditions as the multiphase flow problem is extremely difficult to analyze. Fortunately the introduction of the computer in the petroleum industry has enhanced the investigation of the multiphase flow problem. Rapid computation provides a means for comparison of individual provides a means for comparison of individual methods and an instrument for the development of new correlations. Three of the best correlations were chosen and evaluated; the Hagedorn and Brown, Duns and Ros, and Orkiszewski methods. The accuracy of these new correlations was determined against multiphase flow pressure drop data from 44 wells. The best solution which was both general and gave satisfactory accuracy for all possible ranges of well conditions was determined. The method of Orkiszewski was found to be most accurate for engineering design usage and was the only correlation which could evaluate a three phase flow condition when water is simultaneously being produced with the gas-oil mixture.
Introduction
Accurate prediction of the pressure drop to be encountered during the multiphase flow of fluids in a vertical well is desired for good engineering data. The lack of reliable pressure drop data and experimental flow pressure drop data and experimental flow apparatus for correlation data gathering represent the inherent problems of obtaining a general multiphase flow model. During multiphase flow in vertical tubing at least four distinct regimes of flow are identifiable. These are usually described as the bubble, slug, transition, and mist flow regions. Figure 1 illustrates the geometrical configuration of the four regions of flow. Bubble flow consists of a continuous liquid phase with little free gas present. As greater quantities of gas evolve present. As greater quantities of gas evolve from the liquid phase, the gas bubbles agglomerate, forming slug-like gas pockets characteristic of the slug flow region. As still greater amounts of gas are released, the transition flow region forms in which droplets of liquid become entrained in the gas pockets. The gas pockets become distorted and approach a continuous gas form.
Dukhan Field (Onshore Qatar) Uwainat Reservoir Optimum Development Scheme
Authors: Hussain Ahmed 
Published: December 2007

ABSTRACT
This paper is a case study that discusses evaluation approach used in determining the development scenario for the Uwainat Reservoir in the Dukhan Field in Qatar. Reservoir simulations performed in support of the project evaluation are presented and results are reviewed.
The simulation study was conducted in two distinct phases. During the first phase, a 3D full field model was constructed and the production history of the Uwainat Reservoir was matched in order to estimate a number of reservoir parameters. The second phase of the study consisted of several 2D cross-sectional models to evaluate the reservoir performances under various exploitation schemes using the history-matched reservoir description. Once the most favourable recovery mechanism was identified from the results of the cross-sectioiial study, several prediction runs were made using the above history matched 3D full field model to determine a number of production forecasts based on selected reservoir development strategies.
The 3D FFN was history-matched through January 1990. Satisfactory matches were obtained both on a field and well basis with relatively limited refinements to the initial reservoir data. The history match indicated the likely presence of two partially sealing faults dividing the reservoir in three separate blocks, a moderately active aquifer and gave an estimation of Kv values across the stylolitic intervals which control the reservoir layering. The results of the cross-sectional study indicated reservoir performances to be influenced by heterogeneity and completion practices, and confirmed peripheral water injection scheme to be more favourable than crestal gas injection giving the highest practical recovery.
Finally, the history-matched full field model was used for predicting reservoir performance at various withdrawal rates. Three development scenarios were studied with plateau rates of 10,000, 15,000 and 20,000 BOPD. A field development plan on the basis of 15,000 B/D plateau production rate appears to be the optimal development scenario.