bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Polymer Flooding in Daqing Oil Field and Analysis of its Favourable Conditions
Authors: Zhiwu Wang , Jingcun Zhang , Yanli Jiang 
Published: December 2007

ABSTRACT
Based on the results of sharp decline in water cut, increase in the oil production rate, and a 5% increase in the recovery factor obtained in a polymer flooding pilot test in a reservoir with positive rhythm in Daqing Oil Field, this paper discusses the favorable conditions for polymer flooding in this oil field, including low reservoir temperature, low salinity and low content of high valence ions both in the formation and injection water, and relatively high oil saturation left in the reservoir after water flooding… etc.; and gives both theoretic and practical basis for a possible extensive application of polymer flooding in Daqing Oil field.
The Development of a Deflocculated Polymer Mud for HTHP Drilling
Authors: Abdon J. C. , Jackson B. L. , McClelland G. S. 
Published: December 2007

ABSTRACT
A High Solids Deflocculated Polymer (HSDP) drilling fluid has been developed and field proven at densities as great as 2 0.9 ppg (156 pcf) and sustained BHST's above 3 00 degrees Fahrenheit. The approach used to develop the HSDP mud had the primary goal of reducing complexity: a minimum number of additives were incorporated into the mud, and each additive was selected on the basis of its performance and limited functionality. Products with more than one primary function or with a strong secondary function were determined to be unsuitable.
The system is composed of a polymer viscosifier, a polymer deflocculant, and a polymer fluid loss agent. Barite is added as needed to develop density, and is the only solid intentionally added to the HSDP system. Viscosity and fluid loss are not developed with clay: this drilling fluid functions best when the MBT is as low as possible. Alkalinity is controlled with sodium hydroxide.
The resulting HSDP fluid is manageable at densities exceeding 20 ppg (150 pcf). System rheology is stable at temperatures as high as 350 degrees F. A ten minute gel strength as low as 10 can be maintained if required. The API LTLP filtration rate can be held below 4 cc, and HTHP filtration rate, as defined in this paper, can be kept below 12 cc economically.
Field application has demonstrated this mud to be very tolerant to contamination with monovalent and divalent cations (Na+, Mg++, Ca++), carbonates (CO3−−, HCO3−), water, oil, and various gases. It is reasonably tolerant to the presence of drilled solids.
A Proposed Technique for Evaluating Multirig Drilling Operations
Authors: Khalaf F. 
Published: December 2007

ABSTRACT
This paper proposes an evaluation technique based on operational efficiencies to evaluate development drilling performance. Three time-based efficiency definitions are proposed. These definitions can be used to evaluate rig controlled operations, other operations not controlled by the drilling contractor, and overall drilling performance. Data compiled from 101 wells (drilled in two offshore fields between 1982 and 1988) are used to give examples of actual field applications. The performance in the same field may not be uniform with depth and could vary with the contractor and the type of operation.
Also, a concept based on the top drilling-performance per field (record well) has been advanced in this paper. It provides a depth-rate correlation between fields with different total well depths. This concept can be used to identify low drilling performance. The results obtained from the efficiency and record-well concepts help determine the best combination of services and techniques to achieve potential improvements in low- performance areas.
Design Parameters for Offshore Well Casing Cathodic Protection
Authors: Seubert M. K. 
Published: December 2007

ABSTRACT
To provide protection from external corrosion to a number of Saudi Aramco offshore oil wells in the Arabian Gulf, a test program was undertaken to develop design parameters for protection utilizing impressed current. Casing potential profile logs showed that 50 amperes per well was required for full protection of the well casing through the corrosive formation. The location of the anodes should also be no less than 400 ft. from the well platform for optimum current distribution. Because of the lack of reliable performance of offshore impressed current cathodic protection systems, this paper also covers the design of the system utilizing anodes with high power output and high resistance to chemicals. The offshore well casing cathodic protection program follows a highly successful onshore program which has been in operation for a number of years.
Procedures for Initializing Reservoir Simulation Models
Authors: Fawakhiri A. Y. , Hassan I. M. , Abed A. F. A. R. 
Published: December 2007

ABSTRACT
The simulation models of large heterogeneous reservoirs require both detail and consistency in the input data. This paper presents the initialization procedures that have been tailored to meet such requirements. The main topics include the construction of the areal and vertical grid systems, the definition of fluid contacts, SCAL and PVT data analyses, and standard measures aimed at securing a representative initialization of the problem to be simulated. The presented procedures are being applied successfully in conducting routine simulation studies for this type of reservoirs.
A Reservoir/Wellbore Model for Multiphase Injection and Pressure Transient Analysis
Authors: Almehaideb R. A. , Aziz K. , Pedrosa O. A. 
Published: December 2007

Abstract
Phase injectivities for multiphase injection processes are studied using an isothermal black-oil numerical model that properly treats wellbore/reservoir interaction. A fully implicit technique for the coupling of wellbore and reservoir flow equations is described. The effect of gravity segregation in the wellbore is taken into account to simulate cocurrent water and gas injection. It is shown that the current techniques used in reservoir simulation for assigning phase injectivities yield inconsistent results when wellbore phase redistribution takes place.
The effect of multiphase flow in the well and in the reservoir during well testing is also investigated. The fully coupled wellbore /reservoir model is employed to study the effect of wellbore phase segregation on buildup pressure response.
Characterization of Carbonate Porosity Using Petrophysical Properties and Image Analysis
Authors: Funk J. J. , Choinski M. C. , Saxman B. B. , Callender C. A. 
Published: December 2007

ABSTRACT
Three techniques for describing pore size distributions were investigated to explain large differences in Klinkenberg b factors for heterogeneous, high permeability, carbonate core samples. Gas expansion permeametry was used to determine gas permeability and Klinkenberg-corrected permeability on a select group of Middle East carbonate cores. Samples with similar high permeabilities (600 - 900 md) showed a factor of 20 variation (0.6-12.8) in Klinkenberg b factors. Mercury injection derived pore size distributions were compared with petrographic image analysis (PIA) and scanning electron microscopy (SEM) analysis results to identify a basis for the range in b factor values.
No method provided a direct correlation with Klinkenberg b values. All methods indicated that samples with high permeability and high b values also had an increase in the distribution of larger pores. PIA results indicated statistically a linear relationship between the number of throats and b factor.
Well Test Design and Final Interpretation Improved by Integrated Well Testing and Geological Efforts
Authors: Ayestaran L. C. , Nurmi R. D. , Shehab G. A. K. , El Sisi W. S. 
Published: December 2007

ABSTRACT
In the last decade, well testing has undergone significant technological changes - evolving from an approach mainly involving the determination of a well's producibility to a sophisticated discipline capable of detecting reservoir heterogeneities in the area around a well. Some of reservoir heterogeneities which have been encountered and analyzed are included in this paper: patches of non-reservoir fades, fault boundaries, and thin shale barriers. Although these examples are from Egypt, the Arabian Peninsula, and Pakistan, the same types of heterogeneities are found in many other reservoirs around the world.
A commonly occurring anomaly in transient pressure tests has been found to be caused by patches of non-reservoir, or impermeable rock within a reservoir zone away from the well. Numerical modelling has provided insight into the pressure effects of different types of heterogeneities and their variations in size, permeability characteristics, and distances from the test well. The areal extent of thin barriers within a Middle Eastern braided stream sandstone reservoir was determined using pressure transient testing. Other field examples show how geological and geophysical data are integrated for a more thorough analysis of faults and other heterogeneities. With appropriately designed well tests, the presence and attributes of various barriers have been defined, such as the distance from the well, and sometimes even the angle between two faults. The geological efforts concentrated on the identification of the type of heterogeneity and its probable direction from the well in addition to the orientation of any barriers detected. Walkaway VSP data provided additional faulting information which could not be determined using well testing. Only an integration of disciplines provided a realistic characterization of the reservoir around the well.
Reservoir Sweep Improvement With Cross-Linked Polymer Treatments
Authors: Mody B. G. , Dabbous M. K. 
Published: December 2007

ABSTRACT
Poor reservoir volumetric sweep efficiency results in bypassing, trapping of such of the in-place hydrocarbons, and in the early production of large volumes of water.
This paper discusses technology and field results of treating wells in reservoirs with natural water drive as well as reservoirs under waterfloods with polymer solutions containing delayed cross-linkers to improve reservoir sweep efficiency.
The continuais monitoring and analysis technique has been applied successfully to selectively treat water saturated zones and to preserve the integrity of oil production. The uniqueness of the profile control system application is the continuous monitoring during the treatment which allows assessment of formation response and provides a valuable tool for treatment design refinement and optimization of injected slug volume.
A large number of wells have been treated utilizing delayed cross-linked polymer systems specially tailored for the specific reservoirs. Continuous reservoir monitoring and analysis of data on-site during the polymer application has resulted in better than an 85 percent success ratio.
Wells treated were cased as well as openhole completions, long to very short pay sections, naturally fractured, and hydraulically fractured. The reservoirs treated were bottom water drive and waterfloods, as well as reservoirs under gas injection. The treatments were performed successfully in sandstone and limestone, as well as dolomitic formations.
Cross-linked polymer treatments have resulted in a significant reduction in water production, and, as a result, many temporarily abandoned wells have been put back on production due to savings in operating costs and enhancement of oil inflow into the wellbore.
Appraisal of Techniques Applied To Stimulate the Deep Khuff Gas Wells
Authors: Abdalla M. Seham 
Published: December 2007

Abstract
The design of stimulation job for deep, tight, sour gas bearing formations at high pressure (7000-8000 psi) and bottom hole temperature in the range of 320°F is always difficult, particularly when an expensive special alloy tubing string and fittings are used.
Factors such as, amount of acid to stimulate a long section of tight dolomitic limestone and the operational constraints (tubing capacity, contact time and tubing susceptibility to corrosion by acid, coiled tubing utilization) dictated a rather critical procedure to be implemented.
A compromise between the large volume of acid required and the expected long time needed to spot with coiled tubing made it necessary to carry out the job in two stages. Accordingly, a small acid wash was spotted at bottom applying enough back pressure to stop gas influx. Then the required volume for matrix acidising was bullheaded within the contact time limit (stimulation rate up to 7.7 BPM at 3900 psi WHIP was achieved). The well was back flowed before bullheading the main acid volume, this played a big role in improving the injectivity
The completion string and coiled tubing were protected by circulating a special inhibitor coat ahead of the acid in addition to the normal inhibitor added to the acid.
Proper spotting of acid across the perforated intervals and the high rate achieved at high pressure while bullheading the matrix acidization volume eliminated the need for costly mechanical or chemical diverters.
The stimulation programme was implemented on four Khuff gas wells. The wells performance following the acid wash and the matrix acidization jobs proved that the acid wash is almost enough to achieve the required potential for such tight formations.
Design of Surface Facilities for a High-Pressure Miscible Gas Injection Pilot Scheme
Authors: Saadawi H. 
Published: December 2007

ABSTRACT
A high pressure miscible gas injection pilot project has been recently implemented in Bu Hasa field, Abu Dhabi. The objective of this pilot scheme is to evaluate pattern miscible gas injection as a potential enhanced recovery mechanism in Bu Hasa North Shuaiba Formation.
The pilot project facilities were designed to inject up to 14 MMscf/D [400 × 103 std m3/d] of gas at a wellhead injection pressure of 5200 psi [35.8 MPa]. The injection pattern is an inverted 5 spot with one injection well, four producing wells and two observation wells.
Designing the facilities for such a project requires the collective efforts of many engineering disciplines. This paper describes the surface facilities and presents the basic philosophy adopted in optimising and designing these facilities for the Bu Hasa Pilot Gas Injection Project.
A Relative Distance Indicator from Gamma Ray Spectroscopy Measurements with Radioactive Tracers
Authors: Gadeken L. L. , Smith H. D. 
Published: December 2007

Abstract
The effectiveness of downhole operations is increasingly being evaluated using gamma ray spectroscopy tools in conjunction with one or more radioactive tracers. The materials placed in the well are selectively tagged with tracer isotopes. The spectroscopy measurements are typically used to distinguish the vertical distributions of two or more tracers which have distinct gamma ray energy signatures. In addition, it is possible to use the characteristic shape of the Compton scattered portion of the gamma ray spectrum to determine qualitatively how far each tracer is located from the tool, to within the depth of investigation of the measurement.
A series of calibration experiments was performed to establish the response of three gamma ray spectroscopy tools to six common tracer isotopes. Two artificial formations were constructed to simulate a typical cased hole environment. In order to investigate radial distribution effects, one test formation was subdivided so the formation region consisted of three annuli. The principal purpose was to determine tool sensitivities to different isotopes so that a weighted-least-squares algorithm could be implemented to process multi-tracer logs. The shapes of the tracer spectra were also evaluated for Compton scattering and photoelectric absorption effects.
The results of this study were combined with extensive field experience to show that, in addition to measuring the relative distribution of the tracer isotopes as a function of depth, it is also possible to make a qualitative determination of the average radial distance from the spectroscopy tool for each tracer. A log example illustrates the utility of this analysis.
Latest Experience in Seawater Injection Operations
Authors: Heraiba F. A. , Allam M. I. 
Published: December 2007

ABSTRACT
This paper describes ZADCO water injection system, basis of selecting major equipment and the philosophy of water treatment. The paper covers the operating problems met during the early stages of start up and the experience gained by which similar problems can be avoided in future projects.
The bacterial growth problems in water injection flow lines is presented along with ZADCO measures for cleaning the lines and maintaining good quality of water at the injection wells.
The paper discusses the water quality monitoring methods, reliability of each and the interpretation of its values.
Impact of Super Permeability on Completion and Production Strategies
Authors: Moore D. M. 
Published: December 2007

Abstract
Unpredictable flood front movement, abnormal well production characteristics, and unique geologic occurrences coupled with an integrated field data collection effort eventually merged to identify and confirm localized as well as areally extensive, interconnected zones of super-permeability in a carbonate reservoir. Super-permeability has been identified in fractures, skeletal-oolitic grain-stones and stromatoporoid-red algae-coral. The preponderance of super-permeability examples, however, point to a coral-like organism, referred to as cladocoropsis, which was dolomitized and subsequently leached out leaving pencil-sized vugs yielding horizontal permeabilities in the darcy range.
The abnormal properties of super-permeability dictated an investigation which would focus on predictive techniques and would also address conformance issues. To accomplish these objectives, geologic, production, workover, logging, geochemical and available historical data was screened. Additionally, two wells, drilled in a known super-permeability area, were logged and cored. Selective perforation completions were performed oh one of the new producers as well as a workover candidate with the objective of minimizing the detrimental effect of the super-permeable zone on overall well productivity.
This paper serves to present general observations on super-permeability and its effect on vertical and horizontal flood performance. Also included is a case study covering a 100 square kilometer portion of a field in Saudi Arabia.
An Evaluatio'n of Various Logging Methods for the Determination of Remaining Oil Saturation in a Mixed Salinity Environment
Authors: Freeman D. W. , Fenn C. J. 
Published: December 2007

Abstract
This paper describes several known log analysis methods and calculation techniques used on a number of wells for determining remaining oil saturation in a mixed or unknown water salinity environment. The results obtained from these various methods are compared with remaining oil saturations obtained from coring with sponge core. In zones where the porosity is greater than fifteen percent and the zone is well swept, the remaining oil determined from the carbon-oxygen ratio agrees very well with results obtained from sponge cores. Due to the shallow depth of investigation of the carbon-oxygen tool, care must be taken to insure that the reservoir zone of interest is free of filtrate.
Reservoir Evaluation of the Permian Gharif Formation, Sultanate of Oman
Authors: Focke J. W. , van Popta J. 
Published: December 2007

Abstract
The Permian Gharif Formation consists of predominantly fluvial and coastal clastic sediments, with one major marine incursion in the Lower Gharif represented by the Haushi Limestone. It overlies the glacio-genic Al Khlata Formation with which it forms the Haushi Group, a stratigraphic unit of regional significance. Both Formations form significant reservoirs in Central and South Oman. They are in turn overlain by the redbeds and carbonates of the Permo-Triassic Khuff Formation. The Gharif elastics are very heterogeneous on scales from 100 km down to microscopic. Oil accumulations occur as single or stacked reservoirs depending on the lateral extent of claystone intervals and a complex hydrocarbon migration and structural history. Single accumulations are often further divided into zones which behave as separate reservoirs during production, depending on the geometry (connectedness) and properties of the sand bodies. Oil properties also vary widely with API values ranging from 12 to 53 and in-situ viscosities ranging from 10000 to less than 1 mPa.s. Combination of very variable reservoir and oil properties hampers prospect evaluation, in spite of the great number of Gharif penetrating wells (over 400) drilled to date in the area. In producing fields, individual wells produce at widely different rates, and also vary in decline rates, and water, gas, and sand production.
The large number of uncertainties make it difficult to optimise development, particularly since the relatively large number of small, marginally economic accumulations do not justify major investments in appraisal drilling, coring, or manpower intensive studies.
However, the desert environment of interior Oman allows a flexible and stepwise development often commencing with temporary facilities, which are gradually-replaced with more permanent facilities as the size and production potential of an accumulation is confirmed by several years of production history from an adequate number of producers. Such early production data also provide valuable information on the reservoir architecture. Newly drilled wells may show preferential pressure depletion or water encroachment which helps in assessing lateral and vertical reservoir continuity. As more fields are brought on stream, the integrated data base emerges on the basis of which production performance in this complex Formation can be better predicted.
Problems Associated with Dual Completion in Sip Wells: A Case History
Authors: El Hanbouly H. S. , Saqqa M. R. , Constantini N. M. 
Published: December 2007

Abstract
The standard dual well completions in ADCO Fields comprise two tubing strings, one single packer to isolate the upper from the lower pseudo reservoir, and one dual hydraulic packer above the top perforations to isolate the tubing/casing annulus from the injected or produced fluids.
The following three main problem areas were encountered with the standard dual completion. Pressure build up in the tubing/casing annulus.Obstructions to wireline tools.Communication between the two strings.
Operational and statistical analysis with regard to the sources of these problems; led to the following conclusions: Damage or unseating of the dual hydraulic packer, the presence of a snap latch in the secondary string and damage to the elastomer seals by the corrosion inhibitor in the packer fluids are the main reasons for the presence of annulus pressure.The 2.3/8″ tubing and associated completion equipment are the highest potential problem components of the well completion. The restricted inside diameter of the 2.3/8″ tubing and its susceptibility to bending/buckling result in obstructing the wireline operations.The presence of a sliding door in the primary string, between the single and the dual packers, and damage to the primary string between the two packers proved to be the main reasons for the communication between the two strings.
Some modifications to the completion design and running procedure were made in order to solve the associated problems.
These modifications proved to be highly beneficial in improving the integrity and durability of the downhole completion.