bluuebunny/crossref_metadata_2025_split huggingface dataset:
Problems and Prospects of Natural Gas Transmission and Distribution in Nigeria
Authors: Igwe G. J. I. , Wami E. N. , Ewili J. M. 
Published: December 2007

ABSTRACT
Natural gas as a raw material, is produced in large quantities in oil and gas wells in Nigeria. Although produced in large quantities, the lack of effective transmission and distribution systems results in a greater percentage of this energy source being flared off, thereby resulting in wastage of valuable and scarce foreign exchange for the country. In 1983 alone, of the total gas produced, 78.65% was flared, amounting to approximately 106.36 T kcal/year (1.241 GSCF/D). In an attempt to curtail this colossal wastage of energy and valuable raw material, the Federal Government of Nigeria passed a law on gas flaring and imposed a fine of thirty kobo (30 kobo per m3 in 1979 was equivalent to about 45 cents/m3) per cubic metre of gas flared. This yielded little or no result since the oil producing companies found it more convenient and economical to flare the produced gases.
Based on the above premises, a pipeline network for natural gas distribution for Port Harcourt city was designed with the aid of Hewlet-Packard HP-85 computer. A static design model was used and optimization of the network was carried out on the main pipeline diameter such that no pressure or technological specification was violated. The distribution network was designed to have a capacity of 522 Mscf/D (14.62 Mm /D) based on an estimated gas supply/demand for thirty years in Port Harcourt city. The distribution pattern to the residential areas was based on population density of the city. The total length of the network was 16.6 miles (26.72 km). The maximum and minimum pressure specified at any point in the main pipeline were 300 (2067 kPa) and 100 psi (689 kPa) respectively. The design was also carried out within the compression ratio range of 1 to 1.6, and diameter of 40.64 to 96.52 cm (16 to 38 in) of the main pipeline. The design was performed for inlet pressures ranging from 150 to 200 psi (1033.5 to 1378 kPa).
Managing Gas Supplies In The Deregulated Markets Of The 1980's
Authors: Naylor J. D. , Ferries N. R. 
Published: December 2007

Abstract
The U.S. natural gas industry is in a state of evolutionary change as a result of deregulation and competitive market forces. The changes were precipitated by a reduction in demand and an increase in supply in response to a regulated increase in prices. The resulting "bubble" of excess gas deliverability led to the development of spot markets and a sharp drop in spot prices. Government has now acted to deregulate the business, removing price controls and opening access to interstate pipeline transportation. As a consequence, producers today are faced with great challenges and opportunities in the management of gas resources in the evolving environment. Companies which develop a management strategy to capitalize on the new opportunities should have a competitive advantage in the future.
The challenge of gas supply management today is to be innovative to remain competitive. There is great opportunity to enhance profitability from natural gas assets through improved knowledge and procedures, and through proper resource allocation, prioritization, and organization. As traditional boundaries to competition are removed, new opportunities arise for producers to increase profitability.
In these difficult times it is easy for producers to loose sight of the opportunity which results from the current turmoil. Recent events have been devastating: gas prices are severely depressed, and despite seasonal fluctuations, relatively warm weather conditions have yielded relatively slack demand; the eighteen month gas bubble is in its fifth year with no end in sight; higher priced gas contracts are threatened; take-or-pay issues remain; and the regulatory quagmire appears to be getting worse, or at least more confusing.
Analysis of Natural Fractures Observed by Borehole Video Camera in a Horizontal Well
Authors: Overbey W. K. , Yost L. E. , Yost A. B. 
Published: December 2007

ABSTRACT
A video camera survey was used to examine 2217 feet of horizontal well bore. The air-drilled hole was clean and generally free of debris. More than 200 curvalinear features were noted in the well bore which were interpreted to be natural fractures. A method of orienting the features observed was developed and tested by building a replica of a section of a well bore and examining features with known inclination and orientation. Special video enhancement and playback equipment was used to examine the video tape and orient features in the well bore. Rose diagrams of oriented features show good correlation with rose diagrams of surface joints, seismic trends in the area and fractures oriented from 74 feet of oriented core taken in the well. The video camera survey also revealed that 2-phase flow conditions existed in the well bore. LNG flowed through fractures into the wellbore staining the walls, sublimated, and was produced as a gas. This method of analysis provides information useful in designing completions and stimulations in low-pressure reservoirs.
Gas Well Completions Into Low-BHP Reservoirs Add Reserves
Authors: Duggan J. O. , Langston R. B. 
Published: December 2007

Summary
Mobil has established "Reservoir Management Teams" (RMT) to evaluate and manage major fields. Core team members include a reservoir engineer, production geologists, operations engineer and the operating field foreman. These teams have found that many of the older gas reservoirs were produced to depletion based on the economics at the time of production. Wells were abandoned or recompleted when unable to produce into the 1000 psig (6.89 MPa) line pressure. Others were abandoned for the same reasons at pressures as low as 300 psi (2.07 MPa). The sandstone reservoir completions were usually not stimulated. Fluid blocks caused several premature abandonments. Gas reservoirs got less geological attention than oil reservoirs. Multiple layers were commingled into one zone of completion with some pay left unperforated. Wide well spacing and poor completion practices resulted in bypassing gas reserves in some older fields.
As a result of the above practices, the RMT's have proved that a considerable amount of gas reserves may be recoverable from some of these "depleted" reservoirs. Low BHP reservoirs will need compression, but many of the older fields have a low pressure gathering system in place. However, to recover these reserves, it will be required to successfully complete both old and new wells in reservoirs from 6000–7000 foot (1828–2133 m) with only 300 psi (2.07 MPa) bottom-hole pressure (BHP) or lower. The completion and stimulation procedures needed to successfully complete these very low BHP gas wells require technical expertise along with a large measure of patience. This paper will attempt to illustrate the theory and the techniques used to accomplish very low BHP completions.
The Position of Petroleum in the Development of Energy Resources in China
Authors: Jinhong Zhang , Yupei An , Yuqi Li 
Published: December 2007

ABSTRACT
The energy industries in China have been developing rapidly, with energy output in 1986 26 times as much as in 1949. During this period of time CI949 --19865). raw coal output rose to 894 million tons from 32 million tons. ranking first in the world, or accounting for 20 % of the world’s total; crude oil production increased to 131 million tons from 100,000 tons, ranking fifth in the world? electricity generation went up to 449.6 billion KWh from 43 billion KWh, ranking fifth in the world. The primary energy production in China totalled up to 881 million tons of standard coal, ranking third in the world, next only to the U.S. and the Soviet Union.
Achievements in the Development of Deep Drilling Technique in Sichuan Basin
Authors: Shi Ma Xing , Liusheng Wu , Xunyad Yang 
Published: December 2007

ABSTRACT
Sichuan basin is the primary carbonate deposition basin in China, which is rich in natural oil and gas resources and has a very long drilling history.
The geological conditions in the basin are very complex, which causes a lot of difficulties in deep drilling. Since the end of 1970s, with the development of exploration and drilling in deep formation, a series of complicated technical problems in deep and ultradeep drilling have been well solved. During the recent years, a large number of deep wells and some ultradeep wells have been completed. The economic index of drilling technique has been largely improved.
This paper foresees the future development of deep drilling technique in Sichuan basin.
Study of Residual Oil Distribution During Line Drive Waterflooding
Authors: Zhifang Lin , Hemei Wang , Lei Wu , Zhiqiao Gao 
Published: December 2007

ABSTRACT
The vertical, horizontal, and intra-formation sweeping efficiencies of line drive water flooding are studied by using the methods of testing individual horizons in both production and injection wells, logging for residual oil saturation, pressured coring in check wells and reservoir numerical simulation. The understanding of water encroachment and distribution of residual oil have become the important bases for making adjustment of the oilfield. Both the methods used and our understanding are preliminary, and have to be deepened and verified in production practice.
Practice and Investigation of Drilling and Completiom Techniques for Wells in Heavy Oil Reservoirs
Authors: Jingyi Liu , Fuyuan Zhou 
Published: December 2007

Abstract
This paper systematically discusses the formation, types of reservoir texture of pay zone and physical properties of heavy oil in Liaohe oil field. The current technology of producing heavy oil with high viscosity, high pour point and high asphaltene and resin content is mainly steam injection to reduce viscosity and enlarge flow area. Heavy oil production can be enhanced, when quality solids-free or non-bentonite drilling fluid is used in drilling. Early completion is performed with casing run right above producing zones and cemented with heat - proof cement from casing shoe to surface. Gravel packing outside the screen pipe helps to combat formation damage by cement slurry, prevent sand production and enlarge flow area. The paper analyzes the techniques of drilling and completion applicable to various textures of heavy oil zones. It also gives the causes of sanding-out in gravel packed wells. Effective measures for longer life and better drilling and completion of well are recommended.
Analysis Of Fracturing Pressure And Its Application
Authors: Dian Jiang , Liyun Liu , Shaocheng Yu , Wen Zhu , Wenwen Shan 
Published: December 2007

Abstract
Hydraulic fracturing technique has become one of the most effective stimulation measures for oil or gas well. With the advancement in fracturing technique, the analysis and interpretation of fracturing pressure behavior have been used as a unique fracture testing technique. On the basis of fracturing pressure response, fluid loss coefficient, fluid efficiency, fracture length, fracture width and fracture closure time etc. can.be studied, and the fracture extension and proppant transport in fractures can be inferred qualitatively. All these are used as a guideline and basis in fracturing design, operation and effect evaluation. The method introduced in this paper is based on the method developed by Nolte et al. The widely accepted two-dimensional mathematical model and numerical technique are used, and the whole fracturing process is monitored, analyzed and calculated by a microcomputer, thus a suggestion is made on the evaluation of a fracturing job and the following design is presented. In this paper an estimation of the tenacity of rocks under the formation conditions and the continuous fracture extension by an analysis of the pressure behavior after well shut-in are also discussed preliminarily.
Mechanism And Results Of Spontaneous Current Log To Delineate Thin Flooded Beds In Waterflooding Reservoir
Authors: Chaoqun Niu , Baosheng Liu , Dequi Wang , Shouqian Zhang , Guo Yufeng 
Published: December 2007

Abstract
In water flooding, there is a great need of delineation of thin water flooded beds. The thin flooded beds and the degree of of being flooded can be accurately determined by usine Spontaneous Current Log (SCL) and Improved Spontaneous Potential Log (ISPL). From the characteristics of the change of spontaneous eletric field in pay zones after being flooded, the concept of current increasing factor of flooded beds is put forward and the principle of SCL is demonstrated in this paper. The theoretical equations and curves ot SP and SC in flooded beds are obtained using the principle of superposition. The theory and practice demonstrate that the shifts of the extreme point on the curves are closely related to the state and degree of being flooded and bed thickness. The interpretation methods of SCL and ISPL have been developed. These loss have been proved effective in oil field development.
Numerical Simulation Study Of Effects Of Formation Thickness On Steam Flooding Results
Authors: Shangqi Liu 
Published: December 2007

ABSTRACT
This paper describes the development of a fully implicit two-dimensional three-phase numerical simulator for steamflood. The model consists of three phase mass conservation equations for oil, steam and water, an energy conservation equation phase equilibrium equations and constrain equations
• It takes into account the effects of gravity, capillary force and formation dip, as well as the changes of three phase relative permeabilities with temperature and the heat losses to adjacent strata.
The model solves three-phase mass conservation equations and an energy conservation equation simultaneously. All terms in the equations are implicit with respect to time. The resulted Non-linear fully implicit finite difference equations system is solved using Newton-Raphson iterative method. The time step is automatically selected, its size is controlled by maximum specified changes and maximum practical changes of primary variables in each time step.
Based upon the geological characteristics of Jinglou anticline structure of Nanyang oilfield, Henan Province, the effect of formation thickness on steamflood performance is investigated in detail by using this simulator. The best range of formation thickness of heavy oil reservoir suitable for steamflood is obtained. The results will be useful to steamflood project design in this and other oil fields.
Experimental Study Of Abnormal Phase Behavior Of Microemulsion With Daqing Oil
Authors: Xiren Miao , Shutang Qao 
Published: December 2007

Abstract
In the laboratory study of the phase behavior in microemulsion system formed by mixing various equivalent weight petroleum sulfonates and iso-alchols (isobutyl alcohol, isopentyl alcohol) with Daqing Desassed crude oil, an abnormal phase behavior has been observed. Various formulations of the petroleum sulfonates give little solubilization of the crude, so that it is very difficult to evaluate the best equiepments eight of petroleum sulfonate by use of its solubilization parameters. In this study, procedures, which can form the best middle phase and are related to the phase change, are selected to study the method of increasing the solubilization of abnormal phase behavior crude oil and decreasing the interfacial tension under the reservoir temperature and salinity in Daqing reservoir. Tests show that increasing the av. equivalent weight of the petroleum sulfonates, increasing the carbon chain length of the alcohol and using the mixed alcohols, can improve the solubilization of the crude oil, decrease the interfacial tension, and give a wider range of the salinity for optimization of the displacement-of-oil system.
In the formulation of microemulsion with Daqing degassed oil, a linear relationship between the av. equivalent weight of the petroleum sulfonate and the log of the optimum salinity was obtained. It can be seen from this curve that the optimum av. eq. wt. of the petroleum sulfonate is 522+. Based on this paremeter, TRS-18, PHH and P-HMW with av. eq. weight of 500+ are selected to give a better displacement-of-oil system with a interfacial tension as low as 10-3 m Nm-1.
Results of the tests demonstrate that the method for obtaining an optimum formulation of a microemulsion system proposed by Solager et al. can not be used in case of Daqing abnormal phase behavior crude oil.
The Forces at the Teeth of a Drilling Rollercone Bit: Theory and Experiment
Authors: Sheppard M. C. , Lesage M. 
Published: December 2007

ABSTRACT
The drilling response of a tricone bit (torque and penetration rate as a function of weight on bit and rotation rate) is determined by the details of the indentor motion and the lithology being drilled.
A mathematical model has been developed for the drilling action of a tricone bit which gives quantitative predictions for torque, given the bit geometry and the force/penetration relationships for the individual indentors.
The results of the model are substantiated by a number of laboratory experiments conducted on a fully instrumented bit. Using this device the details of the indentor motion can be analysed and the forces acting on certain of the indentors can be obtained while drilling.
The detailed mathematical model can be simplified to a field interpretation model in which the torque response is described in terms of a contribution from the gouging action of the bit teeth and a contribution associated with the indenting action of the teeth. The relative magnitude of these two contributions depends on the lithology being drilled and the wear state of the bit. The interpretation model has been verified through extensive use in the field, examples of which are documented elsewhere.
Torque Feedback Used to Cure Slip-Stick Motion
Authors: Halsey G. W. , Kyllingstad A. , Kylling A. 
Published: December 2007

Abstract
A novel idea to control the rotary speed incorporates the torque signal, in addition to the speed signal, to produce a more uniform motion of the drillstring. This method is easily incorporated into existing equipment used to control the rotary speed.
We have tested this control system on a full-scale research drilling rig and have demonstrated that such a system can stop slip-stick motion and prevent it from starting. As an additional benefit, such a control system leads to smoother rotation of the bit which can lead to a reduction in axial and lateral vibrations of the drillstring.
In this paper we present the theoretical basis behind such a system and give an example of the experimental results.
Application of Foam Injection in Triassic Pool, Canada: Laboratory and Field Test Results
Authors: Liu P. C. , Besserer G. J. 
Published: December 2007

ABSTRACT
This paper presents the laboratory study and field application of foam injection into the Kaybob South Triassic A Pool, in Alberta, Canada. This carbonate reservoir was under primary production from 1962 and waterflood from 1967. A hydrocarbon miscible flood scheme was implemented in part of Unit No. 1 of the pool in mid 1984. First solvent breakthrough was experienced in late 1984.
The possibility of using foam injection to control gas gravity override and improve sweep efficiency in the hydrocarbon miscible flood has been evaluated. Foam injection experiments were conducted in the laboratory during early 1987 on cores extracted from the Pool. Several commercially available foaming agents were compared under various injection rates, liquid/gas ratios and concentrations. Mobility of gas was reduced by a factor of about 30 by foam injection.
Various ways of conducting the foam injection tests in the field were examined. The procedure of experiment and data acquisition/analysis is discussed. Foam injection field tests were started during September, 1987 in the hydrocarbon miscible flood area. Success in foam injection and propagation has been observed. Results from the field tests are presented.
Evaluation of a Pilot Polymer Flood in the Marmul Field, Oman
Authors: Koning E. J. L. , Mentzer E. , Heemskerk J. 
Published: December 2007

ABSTRACT
In view of the high permeability, fairly high oil viscosity, moderate reservoir temperature, low salinity formation water and availability of low salinity injection water, the Marmul A1 Khlata formation was considered a good candidate for polymer flooding. A pilot consisting of an unconfined 5-spot on a 200 m spacing was initiated in May 1986. After the injection of a water preflush of 0. 23 PV, a polymer slug of 0. 63 PV and a water postflush of 0.34 PV, the total oil production was 59% of STOIIP. The injection of polymer resulted in a sharp increase in oilcut in all four wells. From the viscosity/concentration relationship of the produced polymer and from a detailed rheological characterisation it was shown that no significant degradation of the polymer has occurred. A satisfactory history match of the oilcut response and of the polymer production was obtained with a numerical simulator. From the simulation results and from analytical calculations it was deduced that the reduction of oil in place in the pilot area since the beginning of the preflush was some 50% of STOIIP. This indicates that a pattern polymer flood in the pilot region offers scope for an increase in ultimate recovery of some 25% to 35% of STOIIP compared to primary production with aquifer support. The corresponding amount of polymer is about 2.3 to 3.2 kg of active matter per additional m3 of oil (0.81–1.1 lb/bbl). In a forthcoming pilot extension project polymer flooding will be carried out in an unconfined 5-spot on the original 600 m Marmul well-spacing.
Droplet Size Analysis: A New Tool for Improving Qilfield Separations
Authors: Flanigan D. A. , Stolhand J. E. , Scribner M. E. , Shimoda E. 
Published: December 2007

ABSTRACT
A new approach in the development of oil-water separation equipment is based on droplet size analysis. Droplet sizes are critical information in the design and evaluation of oil-water separators. This paper illustrates how good sampling technique and droplet size analyzers can be combined to make droplet measurements in actual production streams. Droplet size measurements from actual field tests will be shown. Problems associated with droplet size measurements are discussed. Current limitations and future applications of this technique will also be presented. In addition, we have examined how droplet sizes can be used in applications to evaluate separators and other production equipment such as pumps, valves, and strainers.
Engineering Control in Reservoir Simulation: Part I
Authors: Saleri N. G. , Toronyi R. M. 
Published: December 2007

ABSTRACT
This paper presents a broad critique of the current state of reservoir simulation and its applications with an emphasis on its three key shortcomings: (1) lack of established industry standards for simulation (2) non-uniqueness, and (3) inherent uncertainties in reservoir modeling. Examples are discussed to demonstrate how these factors can and have led to misinterpretation and misuse of simulation results.