bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Parametric Analysis of Fruitland Coalbed Methane Reservoir Producibility
Authors: Young G. B. C. , Paul G. W. , McElhiney J. E. , McBane R. A. 
Published: December 2007

ABSTRACT
A "matrix" of sensitivity simulations was performed whereby combinations of key reservoir parameters and operational characteristics were evaluated. The resulting families of gas and water production curves provide an improved understanding of coalbed methane behavior and a means to assess the impact of various operational strategies.
Reservoir Evaluation of the Tangshan Coalbed Methane Prospect, Hebei Province, The People’s Republic of China
Authors: Stevens S. H. , Sheehy L. D. , Zhu Hang , Yuan Ben Heng 
Published: December 2007

Abstract
Based on its large reserves of gassy coals, it is likely that China has significant resources of coalbed methane. Much of this resource lies within the numerous, structurally deformed coal basins of north and northeast China. The tectonic setting and complex reservoir conditions in these basins are distinctly different from coalbed methane producing areas of the U. S. and present new challenges to coalbed methane development. A small volume of methane is currently recovered in China using horizontal boreholes and gob wells for coal mine degasification purposes, but production of coalbed methane from vertical stimulated wells has not yet been achieved.
The coalbed methane prospect described in this paper is located in the tectonically active Kaiping Basin of North China, adjacent to a major strike-slip fault. The primary Permian coal seams are 7 to 11 m thick, of high-volatile A bituminous rank, and located at depths of 700 to 1,000 m. Although the gas resource in place appears to be prospective, the large recent subsidence, extensive folding and faulting, and anisotropic stress regime in the test area underscored the need for a thorough reservoir characterization program prior to completion and production operations. Quaternary subsidence of 300-500 m may have caused the coal seams at Tangshan to be undersaturated in methane. Pre-Quatemary uplift and erosion led to degassing of the coal seams in a portion of the test area. However, geologic analysis helped to locate well sites in areas of favorable gas resource and permeability and provided preliminary estimates of important reservoir properties; reservoir testing being conducted at press time will provide accurate determination of these parameters. Measured and inferred reservoir properties were modeled using reservoir simulation to predict the coalbed methane production potential in the Tangshan test area prior to incurring the costs of a full-scale production hole. These preliminary simulations indicate that coalbed methane wells at Tangshan may have significant production potential, even at relatively low reservoir permeability (1 md).
Estimating Coalbed Gas Content and Sorption Isotherm Using Well Log Data
Authors: Hawkins J. M. , Schraufnagel R. A. , Olszewski A. J. 
Published: December 2007

Abstract
A new general correlation for estimating coal adsorption isotherms using log data has been developed. The "Langmuir Rank Equation," developed with the same dataset used for deriving Kim’s1 equation, provides an improved fit with the measurements. The Langmuir constants are derived from a coal rank indicator and adjusted for temperature. At elevated pressures, such as those in the San Juan basin, this approach may offer a substantial improvement in gas content estimates, as indicated in tests with a limited number of isotherms.
The new correlation, adjusted for the effect of moisture, could be used with well logs alone in estimating gas content (saturated conditions) in coalbeds where no core samples are available. Since the equation provides the entire isotherm, it could also be used in the estimation of reserves. It could also be used when quality checking isotherms. It is important to note that both log-based models (Kim and Langmuir Rank) were developed based on isotherm data, and as such, assume the coal is saturated and cannot be used to identify undersaturated coals.
Infill Drilling in the Moxa Arch: A Case History of the Frontier Formation
Authors: Cipolla C. L. , Kyte D. G. 
Published: December 2007

Abstract
A case history of the Moxa Arch in southwestern Wyoming details the initial development on 640 acre spacing in 1977 through 1982 and the results of subsequent infill wells drilled from 1989 to 1992. The engineering evaluation includes an integration of 3D hydraulic fracture modeling and reservoir simulation with petrophysical and geological studies.
The study indicates that the Moxa Arch Frontier Formation is very heterogeneous with permeabilities ranging from 0.001 mD to more that 0.1 mD. The productive sand thicknesses vary from less than 10 ft to over 70 ft. Effective drainage areas range from over 640 acres to less than 100 acres, with ultimate gas recoveries estimated from less than 1 BCFG to over 5 BCFG. Reservoir and hydraulic fracture modeling indicate that infill drilling on 160 acre spacing (within a portion of the Moxa Arch) would increase reserves by 68% when compared to reserves for 320 acre spacing. Results from new CO2 foam/ISP stimulations did not show significant improvement compared to early water-based fluid and sand treatments.
Postmortem Analysis: Lick Creek Meakin Sand Unit Immiscible CO2 Waterflood Project
Authors: Moffitt P. D. , Zornes D. R. 
Published: December 2007

ABSTRACT
This paper gives a post mortem analysis of the Lick Creek Meakin Sand Unit (LCMSU) immiscible CO2 waterflood project. The project was initiated in 1976 to increase oil recovery from the thin, heavy oil sand. A reservoir simulation study run prior to the project indicated an immiscible CO2 waterflood would recover twice as much oil as a conventional waterflood (oil recovery of 16 percent OOIP for an immiscible CO2 waterflood versus 8 percent OOIP for a conventional waterflood). The project was scheduled to be developed in four stages: 1) cycle all wells with CO2, 2) continuous CO2 injection into the unit injection wells, 3) alternate CO2 and water injection in the injection wells, and 4) water injection only into the injection wells; however, CO2 and water injection in the unit ended prematurely due to the precipitous drop in oil prices in 1986. Channeling of the injected CO2 and water in the immiscible CO2 waterflood project has been a major area of concern. During the course of CO2 injection, a foam treatment and 15 gelled polymer treatments were applied in the unit to increase diversion of the injected fluids and improve sweep efficiency.
Incremental oil recovery from the project, over that of primary recovery, has been estimated to be 1.75 MM STB [0.278 MM m3] of oil to October 1, 1990 (11.1 percent OOIP), compared to an initial projection of 16 percent OOIP incremental oil recovery. The lower than projected oil recovery was due to channeling of the injected CO2 and water in the reservoir and also due to the premature termination of the project due to low oil prices. The results of the 15 gelled polymer treatments conducted to reduce channeling have been favorable overall with incremental oil recovery from the gelled polymer treatments estimated to be 114,700 STB [18,240 m3] from a total of 76,800 active pounds [34,850 kg] of polymer injected or 1.49 STB of oil recovered per pound [0.52 m3/kg] of polymer injected. The use of tracers in identifying high permeability channels was instrumental in the success of these treatments.
Effects of Gravity and Viscous Crossflow on Hydrocarbon Miscible Flood Performance in Heterogeneous Reservoirs
Authors: Pande K. K. 
Published: December 2007

ABSTRACT
Injected solvent composition is a key parameter in the design of hydrocarbon miscible floods. Economic optimization of a field flood requires consideration of the effect of solvent composition on flood performance at the reservoir-scale. In this study, a compositional simulation approach was used to study the effects of permeability heterogeneity, fluid crossflow, and phase behavior on displacement performance in two-dimensional, finegrid (x-z) cross-sections. Results of secondary and tertiary solvent flood simulations in various rock property fields indicate that floods with solvent enrichment at or below that required for development of multicontact miscibility in one-dimensional flow can perform as well or better than floods with richer solvents. A significant change to the current practice of solvent enrichment selection is suggested based on analysis of the simulation results.
Equation of State Characterization and Miscibility Development in a Multiple Phase Hydrocarbon System
Authors: Okuyiga M. O. 
Published: December 2007

ABSTRACT
This paper presents the characterization of an equation of state (EOS) for some heavy oils from the West Sak field on the Alaskan North Slope. The EOS description was needed for evaluating an enhanced oil recovery (EOR) scheme for the field. Various gases ranging from carbon dioxide to enriched hydrocarbon gases have been evaluated in the laboratory as potential solvents.
The interaction of the oils with these solvents is dominated by liquid-liquid phase behavior at reservoir conditions. It is further complicated by the occurrence of a third hydrocarbon phase at certain solvent concentrations. These phenomena are quite Important to the development of miscibility. The EOS developed accurately predicts these interactions.
The dissolution of gases in West Sak oil causes significant reduction in viscosity. A corresponding states viscosity correlation was successfully used to predict the viscosity changes accompanying solvent dissolving in the oil.
Compositional simulations of slim tube displacements involving both two and three hydrocarbon phases have been successfully carried out, while elucidating the mechanisms important for miscibility development.
An Evolutionary Approach to Slim-Hole Drilling, Evaluation, and Completion
Authors: Worrall R. N. , van Luijk J. M. , Hough R. B. , Rettberg A. W. , Makohl Friedhelm 
Published: December 2007

ABSTRACT
Shell and Eastman Teleco have developed a Slim Hole Drilling system appropriate for hole sizes less than 6 1/4″ in diameter. Since the project was started in 1987 the system has been used in 46 wells. Nine wells contained 4 1/8″ hole, one down to 5382 meters. Overall progress per day no longer decreases in smaller hole sizes enabling the total well design to be downsized. Cost reduction of up to a quarter (or more in some cases) are thus possible. The smaller scale of operations reduces environmental impact. Extensions such as horizontal, high pressure / high temperature, and floating drilling are underway. Complementary evaluation and completion technology allows Oil Companies to downsize production wells, potentially reducing field (re)development costs. There remain significant opportunities for the service industry to develop complementary "Slim" rigs, equipment, and services.
Designing Wells for Subsidence in the Greater Ekofisk Area
Authors: Bickiey M. C. , Curry W. E. 
Published: December 2007

ABSTRACT
Well deformations in the Ekofisk Field are attributable to reservoir compaction and the related seabed subsidence. In 1989, unusual techniques/tools such as reduced strength cement, intentional leaks and casing elongation tools were utilized to combat the effects of compaction/subsidence and thus prolong well life.
Surface Monitoring of Downhole Vibrations: Russian, European, and American Approaches
Authors: Dubinsky V. S. H. , Henneuse H. P. , Kirkman M. A. 
Published: December 2007

ABSTRACT
Surface monitoring of downhole vibrations, a promising way to improve drilling efficiency, has been the subject of growing recent interest. While the history of vibration monitoring in Russia has been similar to that of Europe, with an initial focus on the effects of lithology, it was subsequently developed into a solution for problems relating to turbodrilling efficiency, the common approach to drilling in Russia. Elf Aquitaine, in France, commenced work for real-time lithological recognition from surface vibrations in the 1960s; drilling optimization evolved as a further application using their Dynametre. ARCO Oil and Gas Company developed a very similar technology to Elf, focussed initially on reducing premature fatigue failures in the drillstring and bit.
All three approaches are now being synergistically combined through cooperation in this area, and contain many identical elements, both in theory and practice, which highlight the basic common physics of these measurements. Field examples of each approach, and practical applications of this technology are presented. A combination of all of the above techniques will improve the contribution made by surface vibration monitoring to drilling optimization.
Formate Brines: New Solutions to Deep Slim-Hole Drilling Fluid Design Problems
Authors: Downs J. D. 
Published: December 2007

ABSTRACT
Advanced slim hole drilling technologies being introduced for creating cost-effective deep exploration and development wells require a totally new type of drilling fluid that minimises parasitic pressure losses while maintaining effective suspension properties at high temperatures.
A set of high-density organic brine systems based on formate salts has been designed to meet these, and other performance criteria visualised as necessary for an ideal deep slim hole drilling fluid. High-temperature-high-pressure rheology and fluid loss experiments, in both conventional laboratory equipment and IFP's fluid test loop, have confirmed that the new brine formulations have good thermal stability to at least 150°C.
The results from many detailed rheological measurements on these formulations will be fed into advanced fluid hydraulic models to validate the original design concept for minimising parasitic pressure losses in deep slim hole wells by using low-viscosity brine-based drilling fluid systems.
New Approach to High-Density Cement Slurries for Cementing High-Pressure, High-Temperature Wells
Authors: Johnston N. C. , Senese Maurizio 
Published: December 2007

Abstract
A new technique has been developed for densified slurry cementing operations employing a new mix-water dispersible weighting agent. This approach has overcome many logistical, quality control and slurry design problems encountered with conventional dry-blended weighting agents.
Field Evaluation of a Novel Inhibitive Water-Based Drilling Fluid for Tertiary Shales
Authors: Reid P. I. , Minton R. C. , Twynam Allan 
Published: December 2007

ABSTRACT
Laboratory tests showed that tetra-potassium pyrophosphate (TKPP or K4P207) gave levels of shale inhibition well beyond that obtained with equivalent concentrations of potassium chloride. A detailed evaluation indicated that stable mud formulations could be prepared which were considerably more inhibitive than other mud systems currently available. Inhibition even approached the level of that observed with oil based mud with some shale types.
Two North Sea field trials were selected to evaluate the field performance of these phosphate muds. In both cases there were extensive formations of very reactive Tertiary shale which were known to be unstable when drilled using conventional water based muds. Each location also provided good offset data from similar wells drilled with both oil based and conventional water based fluids. This allowed the performance and economics of the phosphate muds to be thoroughly assessed.
In both field trials the highly inhibitive nature of the new systems was confirmed when the shale sections remained open and stable for extended periods. However, in both wells the overall performance of the system was disappointing because of severe problems caused by very firm cuttings adhering to the stabilisers. This "accretion" resulted in slow, tight trips to surface, gave problems with blocked flowlines and a rapid buildup of drill solids, which consequentially required higher than planned mud dilution.
The cause of the accretion problem has been investigated and explained. Work is now underway to find a practical solution.
Innovative Slim-Hole Completions
Authors: Ross B. R. , Faure A. M. , Kitsios E. E. , Oosterling Peter , Zettle R. S. 
Published: December 2007

ABSTRACT
The successful development of slim-hole drilling and evaluation technologies has created business opportunities that are contingent on the development of complementary slim-hole well completion technology. The monobore well completion philosophy is presented. Potential applications and limitations of slim-hole completions are discussed. Areas requiring further development are identified.
Experience with Temporarily Sealing Leaking Tubing Annuli with Extended-Life Polymer Gel Plugs in the Greater Ekofisk Area
Authors: Urdahl Hans , Kettl F. C. , Crossley E. G. , Williams T. A. 
Published: December 2007

ABSTRACT
Extended-life polymer gel plugs have met rigorous requirements as a sealant for restoring a barrier in the tubing annulus when tubing-annulus leakage has occurred. These requirements include urgency to restore annulus integrity, dynamic placement in unbalanced well conditions, and ease of removal without milling the tubing. Very attractive economic benefits have resulted.
Through-Tubing Remedial Treatments Using a Novel Epoxy Resin System
Authors: Gunningham M. C. , van Paassen A. S. W. , Samuel A. J. 
Published: December 2007

ABSTRACT
A new formulation epoxy resin system has been developed, with a solvent system that is compatible with high-expansion elastomers. The versatile epoxy resin system can thus be used with through- tubing straddle packers to treat intervals selectively. The system can be used for sand consolidation, water shut-off and cement repairs. This paper describes the laboratory testing of the new system, various applications of the novel epoxy resin and a case history of the first field trial. Laboratory testing of the system has shown that for sand consolidation the system gives 80-90% return permeability while resulting in increases in unconfined compressive strength of typically 50-70 bar. The system can also be used for shut-off purposes, reducing permeability to water by 99%. Gas shut-off may be less effective. The new resin system produces consolidated sand packs with low moduli of elasticity, which may allow them to survive pressure fluctuations better than more rigid formations. The compatibility of the system with high-expansion straddle packers has been field-proven.
A New 3D Hydraulic Fracture Simulator That Implicitly Computes the Fracture Boundary Movements
Authors: Choate P. R. 
Published: December 2007

ABSTRACT
A new 3D hydraulic-fracturing simulator, GEOFRAC, is described that implicitly couples the solution of the fracture boundary movements with that of the fluid pressure and fracture width profiles over the fracture face. Results obtained with the new simulator are shown to be strictly consistent with its underlying assumptions for a simple case - a condition that may not always be true for the results of commercially available simulators. This difference in the results is shown to relate to the improved numerical procedures that have been implemented in the new simulator.
Application of a Pressure Analysis Expert System During Exploration Drilling
Authors: Tangen Kjell , Baleix J-M. 
Published: December 2007

Abstract
DAPEX (Detection of Abnormal Pressure while Drilling EXpert system) is an expert system which monitors and analyses drilling parameters in real-time during drilling. Its purpose is to perform a comprehensive pressure analysis based on data available from several sources, including surface measurements, downhole measurements (MWD) and predicted geological data. The system identifies abnormal pressure conditions as well as diagnoses their origins.
Tracer Analyses in Stratified Reservoirs (Determination of the Permeabilities Profile)
Authors: Bedrikovetsky Pavel 
Published: December 2007

ABSTRACT
In this paper we discuss the problem of the reservoir characterisation from the tracer test data. Oil-water rates and tracer concentration on the productional wells are available. The problem is to determine the permeability profile.
The new pseudorised equations for the displacement of oil by water with tracer in heterogeneous stratified reservoir are derived. Analyses of the tracer wave propagation into the layer cake reservoir during the waterflooding was given on the basis of analytical solution of the direct displacement problem. Exact analytical solution of the inverse reservoir characterisation problem provides explicit formulae for the profile of permeability.
The method developed was applied for the interpretation of pilot test on gas injection in the Vuktyl field (Russia, Timan-Pechora region). The results obtained from the tracer analyses data fits well with the data of logging and core analyses.
Clair Discovery: Evaluation of Natural Fracturation in a Horizontal Well Drilled in the Basement and Producing from Overlying Sediments
Authors: Fait Urban , Guerin Gwenaël , Retail Phillipe , Evans Martin 
Published: December 2007

ABSTRACT
An extensive fracture analysis was performed in a highly deviated to horizontal well drilled in the basement of the Clair discovery, U.K.C.S. Fracturation is the key factor for the well productivity since the oil is produced through fractures connecting the horizontal drain to the overlying and adjacent oil bearing Old Red sandstones of Devonian age.
The main objectives of this study was first to determine and characterize the fracturation pattern along the well, and then to establish the relationship between the fracturation pattern and the possible producing zones identified from the production log interpretation.
The fracturation methodology which was adopted for the fracturation analysis is described in the paper and is based on the descriptions of cores and on the interpretation of openhole logs comprising classical logs, full waveform acoustic log, borehole televiewer log and production log The high resolution televiewer information was calibrated to fracture characteristics determined from the seven cores taken in the Basement and extended to the scale of the well by use of the Full Waveform acoustic log information.
The fracture system in the basement is characterized by several patterns of different scales. The major fractured intervals, spaced between 100 and 150 m, were interpreted to be interacting with a secondary fracturation pattern more closely spaced around 15 to 40 m. These fractured intervals correlate well with the producing zones identified from the production log interpretation.
To complete the fracturation analysis, a comparison between the determined fractured intervals and drilling parameters (ROP, downhole torque and gas shows) was done. It is found that at least two of these parameters respond as the same time to fractures during drilling.
It is believed that detection of the major fracture zones can be possible during the drilling phase of any well drilled in the basement.
The application of the described methodology is highly recommended on future wells with similar objectives.
Successful Safety Management: Five Years of Effort Pays Off
Authors: Grundt H. J. , Lindeberg Reidar , Nygård Morten 
Published: December 2007

ABSTRACT
Statoil was established as Norway's state oil company in 1972. Following a period of exploration and project development, the company became operator of several onshore and offshore facilities in the mid ‘80s, through friendly take-overs and exercise of options.
The paper describes the initiative taken by corporate management in 1987 to harmonize different safety cultures and to improve Statoil's Safety Management System to facilitate effective risk control. A six point plan for improvement and other safety measures of a motivating nature has now been successfully implemented. Additional measures are now being proposed to ensure continued reduction of occupational accidents and overall risk exposure.