bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Aerated Fluids/Foam Drilling Hydraulics Simulators Against Field Data
Authors: Nakagawa E. Y. , Silva Valter , Boas Mário B. V. , Silva P. R. C. , Shayegi S. 
Published: December 2007

Abstract
The application of light-weight compressible fluids in deep-water offshore operations will soon be a reality. An important factor in the design, accompanying and post-analysis of such a project will be the prediction of reliable downhole pressures, which are expressed in terms of Equivalent Circulating Densities (ECDs). Obtaining dependable ECDs for aerated (gasified) fluids and foam is more difficult than for single-phase fluids, since in the former ones the drilling mud has a gas phase in its composition. Drilling hydraulics simulators can be an important tool in the prediction and analysis of ECDs. There are both steady state and transient computer simulators available for ECD prediction, however their results need verification for different scenarios and different liquid/gas combinations.
In an effort to determine the most suitable simulator program for different well geometries, light-weight fluids and a range of liquid/gas combinations, real-time measured field data were analyzed and compared to bottom-hole pressures predicted by four different drilling hydraulics simulators. Additionally, the principle aspects of these drilling hydraulics simulators were compared based on the following characteristics: accuracy, user interface, numerical stability, and convergence.
Current Materials and Devices for Control of Fluid Loss
Authors: Ross Colby M. , Williford James , Sanders Michael W. 
Published: December 2007

Abstract
The purpose of this paper is to provide the oil industry completion engineers with a workable method for selecting the appropriate fluid loss control systems for their completions.
Fluid loss has long been recognized as a major concern when determining completion costs and assessing well management. For this reason, much research has been dedicated to investigating various methods and equipment to address the scenarios from which fluid loss results. Numerous papers have been written over the years on fluid loss control during well completion and workover. Many of these papers describe a specific method that has been used to address the problem, and a number of innovative devices and fluids have been developed. Most of these devices or systems have been addressed individually in the literature or as comparisons between products that are similar in design and function. Little has been provided on evaluating the merits of a variety of systems in an effort to provide a means of selecting an appropriate solution on a well-by-well or situation basis. This paper provides an in-depth discussion on the benefits, limitations, methods of operation, and possible applications for each of the methods and equipment currently in use.
Development of a Wireless Coiled Tubing Collar Locator
Authors: Connell Michael L. , Howard Robert G. , Moore Darrell W. 
Published: December 2007

Abstract
Achieving proper depth control with coiled tubing has been a problem since the service was introduced, and several improvements have been attempted with limited success. A newly developed tool overcomes depth-control problems by providing accurate depth locations of downhole devices. This tool allows real-time depth indication with standard coiled tubing, and requires no logging cable.
Implementation and Performance of a Microbial Enhanced Oil Recovery Field Pilot in Fuyu Oilfield, China
Authors: Ohno K. , Maezumi S. , Sarma H. K. , Enomoto H. , Hong C. , Zhou S. C. , Fujiwara K. 
Published: December 2007

Abstract
Since 1996, a Microbial Enhanced Oil Recovery (MEOR) field pilot is being conducted as a joint collaborative research project between Japan National Oil Corporation (JNOC) and Jilin Petroleum Group Company Limited (JPGCL) in Fuyuoilfield, Jilin Province, China. The primary objective was to increase oil recovery from a shallow sandstone reservoir that had been waterflooded for over 20 years.
Three microbes have been identified, evaluated, and put to test in the reservoir through huff-n-puff tests during which incubating conditions for microbes were optimized in surface facilities. Four tests with molasses only were conducted and evaluated against those with the microbial solution. Also, an advanced gene-targeting bio-technique, PCR-RELP, was applied to quickly identify and monitor the target microbes.
Significant reductions in watercut and increase in oil production rate were observed in most wells, and they sustained for over 6 months demonstrating the potential of MEOR process. Tests also confirmed abilities of microbes to survive and propagate under reservoir conditions. Preliminary evaluation of fluid analysis and production data indicates that they help increase formation water viscosity, lower water pH and produce gases, notably CO2. Additional huff-n-puff tests and laboratory studies using cores from two newly-drilled wells are underway. The implementation of the final phase of continuous MEOR flood is planned for mid-1999.
Angsi: Malaysia's 1st. Tight Gas Development
Authors: Gopalakrishnan Ganesh , Shawari Razli , Kassim Kamal , Naguib Ab Majid Mohd , Nor M. Nazri M. 
Published: December 2007

Abstract
Angsi Field, the first tight gas development in Malaysia is being developed for start-up in 2002 to meet gas supply commitments.
Productivity from hydraulically fractured wells and recovery from tight sands are major factors in Angsi development planning. An accurate assessment of the physics of fluid flow dynamics within this type of porous media is critical to project success.
A full-field model was constructed using an in-house reservoir simulation package. The objectives of this study were to assess the uncertainties surrounding the productivity of hydraulically fractured wells, expected gas recovery factors and other factors which could impede productivity and recoveries.
This paper discusses the reservoir simulation results and the optimum case that was used as the basis for the field development planning and describes briefly the pre-drill hydraulic fracture simulation design.
Reservoir Simulation of Waterflood Pilot in Naturally Fractured Spraberry Trend
Authors: Putra Erwinsyah , Schechter David S. 
Published: December 2007

Abstract
The Spraberry Trend Area in west Texas presents unusual problems for both primary production and waterflooding. Primary production under solution gas drive recovered less than 10% of the oil in place. After more than 40 years of waterflooding the current oil recovery is still less than 12%. In order to improve the reservoir performance in the Spraberry Trend Area, our studies focused on characterization, modeling and simulation of the Humble Waterflood Pilot. A pilot model was constructed using a three-phase, three-dimensional, dual porosity simulator (ECLIPSE).
Lack of understanding of two key issues are addressed, stress-sensitive permeability and rock wettability. These parameters appear to have a dominant effect in reservoir performance. This study emphasized detailed analysis of the stress-sensitive option used in the simulator by developing a numerical model of solid deformation and stress-pressure dependent permeability using a fully implicit finite-difference scheme. The numerical modeling of spontaneous and forced imbibition experiments using Spraberry core plugs were also conducted to investigate the wettability of the Spraberry matrix. These analyses may be helpful for understanding reservoir behavior and reducing uncertain parameters.
Several studies were conducted after successfully matching waterflood pilot performance. The waterflood pilot model was applied to run a series of sensitivity simulations for horizontal wells, well injectivity optimization, cyclic waterflooding, and other scenarios that could be useful to increase reservoir productivity. Based on results of waterflood pilot scenarios, this study may be able to provide guidelines for field development in the Spraberry Trend Area.
Plug-and-Abandonment Technique for Geothermal Wells Reduces Operators’ Costs
Authors: Courville Perry , Anderson Bryan 
Published: December 2007

Abstract
Because of the instability of the oil industry, operators must continually investigate new techniques and equipment to reduce operational costs. This paper will discuss four case histories involving an innovative well-intervention technique in which a coiled tubing unit (CTU) was used to deploy and set bridge plugs for plug-and-abandonment operations in geothermal wells. By using specially designed coiled-tubing (CT) tools, operators eliminated rig time and formation cooling time, thus reducing operational costs. When job designers assessed the job requirements and service options, they considered the following factors:In geothermal fields, pumping into a well to perform a kill operation for plug-and-abandonment techniques (required for conventional rig equipment) can affect the production of neighboring wells.Bradenhead pumping or pumping from the surface into a well for a kill operation is not always possible unless a kill string or workstring is deployed to a certain depth.The expense of rig time and production loss can affect operational costs.
Coiled tubing has been widely used in the oilfield industry because of its versatility and economy. When CT was first introduced, its primary advantage was that it could perform operations faster than a rig because of its increased pipe-moving capability. CT is now recognized for its capability to perform services with the wellbore in an underbalanced state. Specific tools that have been developed for CT operations have supported the increased scope of applications and have increased operational safety and reliability.
In the case histories presented, CT was used under live well conditions to deploy and set up 13 ⅜-in. bridge plugs for plug- and-abandonment procedures. Pressure-operated setting tools allowed entry into these geothermal wells under flowing conditions and allowed operators to successfully set drillable packer mandrels that have bridge plugs installed.
This paper will discuss the operation of setting tools, procedures for running the plugs, and obstacles that must be considered for operators to perform a successful plug-and-abandonment operation.
Application of Horizontal Well in Heterogeneity Gas Condensate Reservoir
Authors: Muladi A. , Pinczewski W. V. 
Published: December 2007

Abstract
As a result of a low pressure around wellbore, a liquid condensate saturation ring radially propagates the well reducing the relative permeability to gas. This phenomenon can occur even if the average reservoir pressure remains above the dew point pressure. Unless the pressure gradient stabilises around the well, the condensate ring continues to grow and the gas-oil ratio varies accordingly.
This paper presents application of horizontal well in heterogeneity gas condensate reservoir. Horizontal wells theoretically can improve productivity due to minimizing pressure drop around wellbore (higher PI). The primary goal of the study is to examine the difference in production performance between horizontal and vertical wells for different heterogeneities in gas condensate reservoir. Result demonstrate the effect of heterogeneity and average permeability values. It is shown that level of heterogeneity was found to have no effect in production performance but the layering pattern or distribution of heterogeneity was found to have more important effect.
A Successful Example of An Offshore Marginal Oil Field Development—A Case History of Wei 11-4 Oil Field in Beibu Gulf Basin
Authors: Hongji Yu , Shunqiong Song 
Published: December 2007

Abstract
During the feasibility assessment of development of the Weizhou 11-4 oil field, which is considered as a marginal field with no development potential by two foreign companies, we did our best to lower the geological risks and optimize the development plans. The field was proposed to develop by using irregular dense well pattern based on the existing development facilities and put it into production. During production drilling, completion and production, we modified the development program based on the variations of the geology and production performance, and obtained good economic benefits and thus achieve a successful development of a marginal field.
Exploration/Appraisal Well Drilling Experience in Block A-18 of the Malaysia-Thailand Joint Development Area.
Authors: Desa Mohd Latif , Anuar Anwar Hisham Zainal 
Published: December 2007

Abstract
Over a period of 3 years, beginning May 95, Carigali Triton Operating Company, Operator for and on behalf of PETRONAS Carigali (JDA) Sdn Bhd, Triton Oil Company of Thailand (JDA) Ltd, and Triton Oil Company of Thailand Inc., Contractor to Malaysia-Thailand Joint Authority (MTJA) for JDA Block A-18 have drilled a total of 16 exploration wells in the block.
The first well, Cakerawala 1A was spudded in May 1995 and the most recent well Bulan-3, was completed in July 1998.
Challenges, such as shallow gas anomalies, pore pressure uncertainties, tool temperature limitation, and lost circulation risk, have resulted in progressive well design changes. In general, most wells experienced abnormal pore pressure increases below 6,000 ft. The rate of increase differs between wells with the most extreme at 0.6 ppg/100 ft. Even though offset well pore pressure information exists, it served only as a qualitative guide.
Temperature was an important factor in the well design, especially mud selection. Temperature exceeding 400°F was recorded in one of the wells where oil based mud was used. This high downhole temperature had also resulted in frequent "cooling wiper trips" being required during formation evaluation activities to cool the wellbore due to logging tool temperature limitation.
The existence of shallow gas anomalies and lost circulation risk also contributed to the well design approach. However, by adhering to CTOC shallow gas procedures and by casing-off the loss circulation zones, the impact of these factors were minimized.
This paper will share and discuss the experience of CTOC in drilling these wells, such as well design changes during drilling to accommodate actual drilling results as well as the methods and procedures adopted to successfully drill these wells.
Progressive Cavity Pump-Jet Pump Production Method for Lateral Directional Drilling Well
Authors: Jun Zhu , Zheng Jiang Min , Fen Xu Xiu 
Published: December 2007

Abstract
To realize the high comprehensive production economic benefit of the lateral directional drilling well, one method, progressive cavity pump-jet pump production method, for lateral directional drilling well is studied in this paper. Its principle is introduced and the main characteristics are analyzed. The field test result for one well is given too. The experiment verified that the progressive cavity pump-jet pump production method has deeper pump setting depth and less investment cost and higher well oil-producing compared with other artificial lift methods. The progressive cavity pump-jet pump production method is one advanced and effective artificial lift method for the lateral directional drilling well's comprehensive economic production.
Use of Pseudosteady-State Pressure Distribution to Represent Wells in the Finite-Element Mesh
Authors: Lee Kun Sang 
Published: December 2007

Abstract
In calculating the long-time performance of depletion reservoirs using a numerical method, an accurate and efficient simulation highly depends on the proper grid selection. The treatment of wells can particularly have a strong influence on computed results. In our model, we use a very fine hybrid grid in near-well regions to obtain good resolution in the vicinity of wellbores. For the efficient simulation of field-scale problems with multiple wells of differing production rates, a well model was introduced to reduce the concentration of elements near wells. The model was based on a near-wellbore approximation of the pressure distribution during pseudosteady-state. Well performance calculated in the well model is correlated to the conditions in the appropriate location from the actual well. This approximation overcomes an inaccuracy for fluid flow calculation in the vicinity of wells and can be implemented easily in existing grids.
A numerical model based on the approach was developed for a simulation study. Numerical examples are presented to show the accuracy and computational efficiency resulting from the use of a well model. With the approximation, it was possible to reduce the number of element grid nodes up to 1/3. The level of error due to the approximation was in an acceptable range (&lt; 4%) for all cases considered. The key element to the accurate calculation is the ratio of the effective radius of the near-well region compared to the distance to the nearest boundary.
Sepinggan Field Development: A Cross-Functional Team Effort to Develop Bypassed Attic Oil
Authors: Palar S. , Bowen J. F. , Elim A. , Leger K. P. , Simmonds B. , Fryns G. C. , Hursey M. 
Published: December 2007

Abstract
The Sepinggan SW project was conceived to remedy the problem of increasing water cut and a corresponding drop in oil production from wells completed in the Sepinggan SW fault block. It was felt that the SW fault block required additional delineation wells to determine the true downdip extent of the hydrocarbon column and to recover oil by-passed by the current production wells.
The initial idea was to drill long reach wells from the existing Sepinggan Field platforms. This approach however, had known drawbacks in terms of historically high drilling and completion costs, and a high degree of mechanical risk. Additionally, due to the required high angle from the long reach, some stacked pay potential may have been bypassed.
The cross-functional team working in the field conceived an idea of using existing Stacked Template Structure (STS) technology to provide easier wells to drill, with better well spacing, and dual objectives of drilling downdip appraisal wells and infill wells to maximize ultimate recovery.
This paper will show that due to close coordination among CFT (Cross Functional Team) members and support departments, the project was taken from concept to first production in approximately seven months.
In-situ Redistribution of Dormant Gas Reservoir Energy to Maximise Oil Recovery
Authors: Boersma Diederik , Deutman Robert , Lau Hon Chung , Wassing Bart 
Published: December 2007

Abstract
This paper discusses a novel development concept of internal gas injection, in which the energy of gas reservoirs is used to maximise production and ultimate recovery of depleted oil reservoirs.
The South West (SW) Ampa Block 11 field in Brunei is characterised by highly stratified formations containing numerous, often areally extensive, stacked thin reservoirs alternated with sealing shales. The sequence contains a variation of oil, gas, oil rim and water reservoirs. Due to faulting and reservoir shale-out, Block 11 oil reservoirs are isolated and therefore lack support from an active aquifer. The pressures in the oil reservoirs have declined severely, resulting in low production rates and a low ultimate recovery (current recovery factors range from 20% to 40% for individual reservoirs).
A novel development concept of internal gas injection is now proposed to provide energy to the oil reservoirs at low unit cost. Block 11 contains gas reservoirs that underlie the more shallow oil reservoirs, and contain an abundance of energy. The internal gas injection scheme will be implemented by drilling two "injection" wells. Within each well-bore gas will be produced from the gas reservoirs and injected directly into the oil reservoirs. The process will be controlled using intelligent well completions. The scheme will substantially increase the oil production rates and reserves. The injected gas will be back-produced both during the proposed development and after economic oil production has ceased, without loss of gas ultimate recovery. The proposed internal gas injection scheme is believed to be an industry first.
Systematic Extensive Laboratory Studies of Microbial EOR Mechanisms and Microbial EOR Application Results in Changqing Oilfield
Authors: Deng Dejun , Li Chenglong , Ju Quanyi , Wu Pingcang , Dietrich F. L. , Zhou Z. H. 
Published: December 2007

Abstract
Microbial EOR was extensively laboratory tested to evaluate microbial affects on fluid properties and oil recovery then successfully applied in Changqing Oilfield. Fourteen different items were evaluated in 271 different tests to better understand the mechanisms of microbial EOR. Testing included core flooding, mobility improvement, crude compositional changes and microbe metabolite production and affects. Results are that the facultative anaerobic microbes can degrade the alkanes in crude into shorter chain alkanes and produce beneficial metabolites including carbon dioxide, surfactants and organic acids. The lower oil viscosity and beneficial metabolites are effective at increasing oil production rate and recovery. The lab testing is very complete and systematic leading to performance evaluation of the treatments in twenty-seven wells. Microbial EOR increased production 17.5 tons/day or eighteen percent.
Effective Evaluation and Development of Sha 1 Igneous reservoir in Shang 741 Area
Authors: Yuan Xiangchun , Wu Wei , Sun Guo , zhao Kailian 
Published: December 2007

Abstract
Sha 1 igneous reservoir in Shang 741 area is located in the western portion of the central uplift zone of Huimin basin, China. Multistage eruptions formed pyroclastic rock and lava, with dolomite and other sedimentary rock interbeds. The igneous rock is characterized by irregular shape and complex pore structure. Only porous igneous rocks and fractured dolomite can be reservoir rock. So, the reservoir is very heterogeneous.
The pre-production evaluation of the igneous reservoirs was performed based on 3D seismic, core analyses, drilling, logging, in especial FMI logging and CMR logging, and production data. The emphases of the research were put on the spatial distribution and internal structure of the igneous, the lithofacies of the igneous rock and sedimentary interbeds, the spatial distribution and quantitative description of pores and fractures, especially the microscopic and macroscopic features of the reservoir rocks, and the prediction of the potential reservoirs. Then, the proved reserves were also estimated. 4 development wells were designed and drilled in favorable oil-bearing area and the expected production were obtained.
This paper discusses the evaluation methods and results of the igneous reservoir in Shang 741 area and its development.
Imbibition Studies of Low-Permeability Porous Media
Authors: Akin S. , Kovscek A. R. 
Published: December 2007

Abstract
A systematic investigation of capillary pressure, relative permeability, and fluid flow characteristics within diatomite (a high porosity, low permeability, siliceous rock) is reported. Using an X-ray computerized tomography (CT) scanner, and a specially constructed imbibition cell, we study spontaneous cocurrent water imbibition into diatomite samples at various initial water saturations. Air-water and oil-water systems are used. Despite a marked difference in rock properties between diatomite and sandstone, including permeability and porosity, we find similar trends in saturation profiles and dimensionless weight gain versus time functions. Diatomite is roughly 100 times less permeable than sandstone, yet it imbibes water at rates rivaling sandstone. Importantly, the spontaneous imbibition data when combined with CT-scan images provides a means to determine dynamic relative permeability and capillary pressure functions.