bluuebunny/crossref_metadata_2025 huggingface dataset:
Continuous Orientation Measurement Systems Minimize Drilling Risk During Coring Operations
Authors: Brindley C. P.
Published: December 2007

Complex new field developments and in-fill drilling programs have placed extra emphasis on the work conducted by an oil company's geological and petrophysical departments. Core samples retrieved from the wellbore are a key source of data to these groups. Secondary and tertiary recovery projects have placed an extra premium on these core samples being oriented to assist in fracture orientation and measurement of directional permeability and porosity.

The traditional survey instrument used to measure the in-situ orientation of a core as it is being cut has been the mechanical film recording system developed for borehole deviation measurement. The use of this system placed certain risks on the drilling operation, as it was necessary to stop drillstring rotation and fluid circulation to make the orientation measurements.

Solid state transducers developed for real time directional surveying formed the basis for the development of electronic survey tools as replacements for the mechanical film systems. The transducers used are stable enough to be used in a "continuous" mode within the coring operation, thus negating all risks previously associated with oriented coring. The impact on the coring operation of taking orientation measurements is now zero.

This paper seeks to outline the development and application of electronic survey tools for core orientation measurements. Advantages of the continuous method are highlighted, and operational experiences on more than 60 wells worldwide to date are discussed.
Teamwork and Technique: Keys to Record Well in Roger Mills County, Oklahoma
Authors: White R. L. , Jolley G. M. , Hampton S. D.
Published: December 2007

Tenneco Oil Company generated a prospect in Western Oklahoma that was not economically viable at the current projected drilling costs. This paper presents an innovative drilling contract and aggressive techniques utilized to make the prospect economical. The drilling contract created a teamwork atmosphere between the contractor and operator that resulted in a safe and record setting 13,380’ well.
Accurate Flow-Out Measurements for Kick Detection, Actual Response to Controlled Gas Influxes
Authors: Orban J. J. , Zanker K. J.
Published: December 2007

Early reliable detection using delta-flow offers the best approach to reducing the hazard associated with well kicks.

This paper describes the performance of a recently introduced return-line flowmeter for kick detection.

Controlled gas kicks were generated in a 1000 meter (3300 ft.) well and measurements performed. With the use of the new flow-out sensor, kicks were always detected a few minutes after the kick started downhole.

The new flow sensor allows direct measurement of influx during a "flow check" procedure.

This accurate flow-out measurement, together with the traditional flow-in evaluation from a pump stroke counter, is sufficient for kick or loss detection on most rigs when associated with continuous trend analysis of the variations in the ratio between flow-in and flow-out.
Expansion: Anti-Fluid Migration Technology Solves South Texas Fluid Migration Problems
Authors: Bour D. L. , East L. E.
Published: December 2007

Pressurized sands from water disposal caused corrosion problems in a south Texas production field. New casing strings were cemented inside older strings which had parted or had developed holes at the water disposal zone. Various cement blends were used, but one was especially successful in preventing annular invasion of the corrosive brine. The blend incorporated a chemical expansive admixture along with a unique and new anti-fluid migration additive. Cement blends of this type were used to cement these problem wells with excellent results. New wells in this area were also successfully cemented with the same type of blend, yielding excellent bond logs across the troublesome water zone.

Detailed information is given describing the various properties of the cement slurry. Case histories are presented detailing the problem and success of the special cement slurry.
Inflatable Packers: Production Application
Authors: Walsh M. D. , Holder D. J.
Published: December 2007

A retrievable packer and bridge plug have recently been developed which are designed to be run with coiled tubing for production operations. This 3.375-inch [8.573 cm] OD tool (reference is to packers and plugs collectively) is set and released within coiled tubing's pressure and pull limitations. An inflatable packing element is inflated with pumped fluids and is used as an anchor and seal. The inflatable element allows passage of the tool through tubing restrictions and can then be inflated and set in casing up to 7-inch [17.78 cm].

The authors have been associated with 29 jobs in the West Operating Area of Prudhoe Bay utilizing these tools. These tools have proven effective in their primary application of mechanical isolation for selective zone stimulations through coiled tubing. This paper provides a discussion of the tool, insight from the authors' experience into the application and limitations of these useful tools, as well as operational guidelines developed for their running and retrieval in production applications.

Accurate depth control is a concern when small intervals are available for setting. Elongation of coiled tubing under the pressures required for setting these tools is discussed. Operational guidelines are presented for determining length changes as a function of depth and pressure to ensure accurate control of setting depths. Depth control procedures presented here have permitted the setting of these tools within 15 inches [38.1 cm] of target at depths over 10,000 feet [3048 m] in deviated wells under favorable completion conditions.

Brief discussions of cost benefits and downhole injection chokes are also included.
Field Measurement of Viscosified Fluids
Authors: Hashemi R. , Caothien S. , Rovig J.
Published: December 2007

Oilfield polymers such as HEC (Hydroxyethyl Cellulose) and Xanvis™ (Xanthan Gum) solutions are filtered to remove microgels and minimize formation plugging. Mechanical and hydraulic shearing of the gel alter the rheology of the polymers. Field data on various concentrations of HEC and Xanvis show the effects of each shearing mechanism on polymer viscosity, sand fall rate, and leakoff. A guideline for the on-site evaluation of the quality of sheared and filtered HEC is presented so that excessive shearing and unnecessary degradation of the gel can be recognized and prevented.
Don't Forget Consolidation
Authors: Beatty W.A.
Published: December 2007

This paper was prepared for the SPE Symposium on Mechanical Engineering Aspects of Drilling and Production to be held in Fort Worth, Tex., March 5–7, 1967. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor of the appropriate journal, provided agreement to give proper credit is made.

Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers Office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Proper application of lease consolidation and commingling methods can provide significant reductions in investment and operating costs for oil producing properties. Advantages, limitations, and possible dollar savings of various field proven consolidation methods and L.A.C.T. systems are reviewed.

Introduction

A continuous search for more efficient oil production methods has been necessitated by the ever increasing cost of labor and materials. Consolidation of oil producing properties is one important cost cutting method often overlooked. L.A.C.T. opened the door for consolidation/commingling applications by providing an accurate and dependable means of continuously metering and delivering oil from the producer to the purchaser. However, sufficient savings are seldom realized by L.A.C.T. alone unless utilized as an integral part of consolidation. Conversely, lease consolidation can be accomplished without L.A.C.T., but such applications are rare. Field proven consolidation methods will be described and the benefits, savings and limitations discussed.

METHODS

For the purpose of this paper, consolidation/commingling techniques will be divided into two general methods: the Multi Custody Transfer method in which crude from two or more leases is commingled after sale by the producer and the Single Custody Transfer method in which the crude is commingled at some point prior to sale. The orderly development from basic to more complete consolidation will become apparent as the two methods are discussed.

Multi Custody Transfer: The flow pattern for this basic consolidation method is illustrated on Plate No. 1. Production from each lease or zone is transported by individual flow line to a centralized battery site, treated by a separate treater and stored in separate tanks. A multi lease automatic custody transfer unit delivers the oil from the individual lease storage tanks to the pipe line and records the volume on the L.A.C.T. master meter register and the appropriate lease oil registers.
Analysis of Computational Procedures for Multicomponent Flow in Pipelines
Authors: Goyon J. C. , Shoham O. , Brill J. P.
Published: December 2007

The compositions of vapor and liquid phases of a multicomponent system are functions of pressure and temperature. Therefore, the phase behavior of a fluid transported through a pipeline must be coupled to the pressure-temperature calculation algorithm. Both the Soave Redlich-Kwong and the Peng-Robinson EOS’s were considered.

A new procedure to calculate pressure and temperature profiles for multicomponent two-phase flow in pipelines was developed. This method, based on direct flash calculations at each pressure and temperature of interest, was compared to the method used by previous investigators based on interpolation of external arrays of physical properties.

The new procedure was found to be more accurate and easier to use than the one based on interpolation of external arrays. This was especially true when calculations were performed near the critical point.
The Use of Systems Analysis in the Design of a Gas-Lift System
Authors: Stinson R.
Published: December 2007

This paper deals with the use of the total system approach in the evaluation and design of a gas lift system for a single or multiwell system. Computer generated analysis are used to demonstrate the effects tubing size, gas injection pressure and separator pressure have on production rates and gas volume requirements for wells within the system. The effects of gas injection volume, compressor suction pressure and discharge pressure on compressor horsepower requirements are considered in analyzing the gas lift system design. The evaluations in this paper are based on a group of wells with similar reservoir characteristics. The analytical techniques shown in this paper would be applicable for the analysis and design of a larger type system incorporating wells with varrying production capabilities.
Pressure Pulsing Waterflooding in Dual Porosity Naturally Fractured Reservoirs
Authors: Peng C. P. , Yanosik J. L.
Published: December 2007

Conventional waterflooding in naturally fractured reservoirs can be uneconomic due to poor oil recovery performance. A technique to improve the oil recovery performance is pressure pulsing water-flooding. The technique is cyclic and consists of alternately pressuring and depressuring the reservoir. During the pressuring phase, water is injected and forced under high pressure to flow from the fractures into the matrix. Fluids are produced from the reservoir during the depressuring phase. The reservoir pressure is allowed to drop until either the oil production rate becomes too low or the producing gas-oil ratio becomes excessive. Cycles are repeated as long as the process is economic.

This paper presents results of a simulation study to determine the important parameters which affect the success of pressure pulsing waterflooding. A dual porosity generalized compositional model was used for the simulations. The results show the success of pressure pulsing waterflooding is dependent on the interconnected fracture network, relative permeabilities and oil fluid properties. The fracture network allows injected water to move rapidly away from the wellbore throughout the reservoir system. Matrix relative permeabilities affect the amount of oil and water retained in the matrix rock during the depressuring phase. Gas collapse during the pressuring phase allows water to enter the matrix rock, and gas evolution in the depressuring phase drives oil from the matrix rock into the surrounding fractures. It is illustrated that the effectiveness of pressure pulsing waterflooding can be improved by conservation of gas in the reservoir and/or by supplemental gas injection in the pulsing cycles before water injection.
Jabiru Field Simulation: A Case History
Authors: Wallace T. D. , Balnaves C.
Published: December 2007

The Jabiru field forms part of a northeast-southwest trending complexly faulted, structural high. Massive marine sands of Juassic age and of excellent quality are truncated by two unconformity surfaces. The 60 m oil column is underlain by an extensive aquifer which provides strong bottom-water drive. The field came on stream at 2100 m3/d in August 1986 and is currently producing through two subsea wells to a floating production facility at a rate of 4540 m3/d. Two further wells are planned to come on stream by mid-1988, increasing field potential to about 8740 m3/d.

Reservoir simulation has played a key role in the development of the Jabiru field. Initial models ranged from 2-dimensional/2-phase radial to 3-dimensional/2-phase cartesian, to allow preparation of and increase confidence in forecasts of field behavior. The most serious limitations of these simulations lay in the geological models used and the prediction of water breakthrough.

This paper is intended as a case history discussing the evolution of the reservoir simulation models through five significant revisions and compares the results obtained at each stage. The variation of model parameters is presented always with the aim of understanding a complexly faulted reservoir experiencing strong bottom-water drive. Different solution methods and gridding options have been employed and emphasis is placed on the need to be judicious when applying several simulator options concurrently. In particular the use of segregated flow and the relative merits of placing a finer grid around wells to model the coning behavior are discussed.

This paper is aimed at the practicing reservoir engineer and, by frankly outlining the route undertaken by BHP Petroleum, some of the pitfalls and problems as well as benefits of reservoir simulation are exemplified.
Fracture Design Considerations in Naturally Fractured Reservoirs
Authors: Cipolla C. L. , Branagan P. T. , Lee S. J.
Published: December 2007

The ability to effectively enhance production through hydraulic fracturing is dependent on an accurate description of the reservoir production mechanism(s). Fracture designs may differ greatly depending on the production mechanism(s). The complex nature of hydraulically fractured reservoirs in which the predominant production mechanism is a set of interconnected, naturally occurring fractures is investigated in this paper. The paper integrates general reservoir simulation results with actual field data from a naturally fractured reservoir in the Piceance Basin, Colorado.

The study investigates a variety of natural fracture/matrix properties and compares the productivity of these naturally fractured reservoirs to homogeneous reservoirs with the same average flow capacity. The paper also investigates the influence of natural fracture anisotropy on hydraulic fracture design. The effect of damage to the natural fracture system is illustrated and compared to analogous homogeneous reservoirs. The economic considerations associated with many of the reservoir production mechanisms are presented.

The results of the reservoir simulations indicate that optimum fracture lengths for isotropic, naturally fractured reservoirs are identical to those estimated for homogeneous reservoirs having the same average flow capacity. Therefore, accepted fracture design considerations to determine optimal fracture length and conductivity can be used in isotropic, naturally fractured reservoirs based on the average flow capacity of the reservoir. However, fracture design considerations are more complex when the effects of natural fracture damage and anisotropy are encountered.
The Evaluation of Oil Saturation Through Casing Using Carbon/Oxygen Logs
Authors: Woodhouse R. , Kerr S. A.
Published: December 2007

Carbon/oxygen logging is used to determine oil saturation in cased holes without knowing formation water salinity.

When the carbon/oxygen tool is used alone, in non-extreme conditions, the accuracy of the interpreted So is calculated to be ±23 saturation units at 20% porosity. The uncertainty increases rapidly as porosity decreases.

Field examples illustrate its potential value and practical problems created by the measurement statistics, borehole fluid changes and remaining mud filtrate.
The Application of a Modular Measurement While Drilling System for Directional Control and Formation Evaluation in Horizontal Wells
Authors: Harrell J. W. , Dickinson R. T. , Wiley W. W.
Published: December 2007

The application of measurement while drilling technology is fast becoming a crucial part of many successful horizontal drilling programs.

The need for accurate directional and geological control is essential in order to meet predefined angle build rates and locate and stay within target horizons. This need is further emphasized in the smaller radius, slim hole, high angle wells that are now being drilled.

This paper describes the application of a modular multi-sensor measurement while drilling system for use in most types of conventional and high angle directional wells for formation evaluation and directional control.

Several case histories will be presented from diverse operating environments covering the following drilling applications: conventional directional build programs, medium radius operations, slim hole drilling, and other special drilling applications.

Finally the paper will cover future measurement while drilling developments and the possible benefits for high angle and horizontal drilling techniques.
The Role of Reservoir Simulation in the Development of Some Major North Sea Fields
Authors: Wood A. R. O. , Young M. S.
Published: December 2007

Many alternatives arise during the development of major oil and gas fields. Reservoir simulation has a firmly established role in helping to select which of these alternatives will give the optimum development. This is especially true in the North Sea where development and operating costs are relatively high and it is cost effective to study options in detail before proceeding in the field.

General reservoir simulation principles are now well known by reservoir engineers but they are summarised in this paper as an introduction for a wider audience.

A case history is presented which shows how reservoir simulation has been important at all stages in the development of BP’s Magnus field. Figures are presented to show how estimated Magnus field reserves have changed with the acquisition of new data and improved interpretation techniques. Reserves histories for other major North Sea fields are also discussed.
An Analysis of Naturally Fractured Reservoir Performance Using a Novel Fractured Reservoir Simulator
Authors: Litvak B. L. , Satter A. , Etebar S.
Published: December 2007

This paper presents our experience in the studies of naturally fractured reservoirs using a state-of-the-art fractured reservoir simulator. Characteristic features of fractured reservoirs were analyzed during simulation of two reservoirs and laboratory imbibition experiments. One simulation study involving a North Sea reservoir required an accurate description of the imbibition processes. Production history and rise of free water level (FWL) in the fracture system were matched by changing the degree of imbibition and fracture porosity in the reservoir. The results of the study were used to justify waterflooding.

For a naturally fractured offshore reservoir in the United States, the simulator was used to predict production performance as influenced by matrix permeability, fracture porosity, compressibility and capillary pressure. The simulation results were utilized in the reservoir development plan.
Elevated Temperature Multiphase Rock-Fluid Properties for High and Low Tension Systems
Authors: Okoye C. U. , Oungpasuk P. , Wang P-H. , Hayatdavoudi A. , LeBlanc J. L.
Published: December 2007

Numerical simulation of steam-chemical oil recovery processes require high temperature multiphase rock-fluid properties such as relative permeabilities and capillary numbers. These parameters are needed to predict and evaluate oil recovery performance and efficiency. Experiments in both Berea sandstone and sandpacks have been conducted to measure relative permeabilities of high and low tension oil-water mixtures at elevated temperatures. A new mathematical model consisting of sets of empirical correlations based on experimental data have been developed for relating endpoint relative permeabilities to both residual and mobile oil-water saturations and capillary numbers to residual oil-water saturations.

The tests were run over a wide range of temperature, 72° to 400°F, and overburden pressure range of 500 to 1000 psia. It is our belief that this model is new for the range of temperature and pressure of steam oil recovery processes with chemical additives. Predictive results made with empirical correlations are in good agreement with experimental results.
Enhancement of Real-Time Hydraulic Fracturing Models with Full 3-D Simulation
Authors: Cleary M. P. , Barr D. T. , Willis R. M.
Published: December 2007

In a major advance over previous capabilities for prefracturing design and real-time field application of hydraulic fracturing models, the ability to accurately handle complex pumping schedules and reservoir conditions has been achieved by developing the capabilities for full three-dimensional hydraulic fracture analysis and combining these with the speed of lumped model simulations. These lumped (spatially integrated) models have already been used for the design and realtime analysis of numerous fracture treatments. Now, a fully 3-D code, based on finite elements and surface integrals, developed as part of a comprehensive field monitoring and analysis project for the Gas Research Institute, is being used to analyze fracture geometries and pressure distributions for many variations of viscosity scheduling and stress barrier placement. Analysis of these 3-D results produces integration coefficients which can be implemented in the lumped models. These coefficients enable the lumped model to accurately account for viscosity and pressure variations in the fracture, and for differences in confining stress magnitude in the strata above and below the payzone. This work allows the lumped models to be made more quantitatively correct by incorporating the essence of full 3-D modelling capabilities without any loss of execution speed. The effectiveness of the methodology is demonstrated by performing simulations with a number of data sets from field operations as input.
Improvement of Massive Hydraulic Fracture Treatments in the Cotton Valley Formation of East Texas
Authors: Pearson C. M. , Lynch K. W. , Schmidt J. H. , McCaslin N. F.
Published: December 2007

In 1986 Arco Oil & Gas Company commenced an on-going development drilling program in the Oak Hill field area of east Texas. The formation of interest was the Taylor section of the Cotton Valley tight gas sand. Wells required stimulation with massive hydraulic fracture treatments due to the extremely low matrix permeability. This paper presents a case history of the stimulation program over an 18 month period during which 28 wells were fractured. The evolution of the fracture design is discussed in six phases of design change and evaluation.

The importance of real-time continuous quality control information is shown for identifying problems which if undetected could lead to an incorrect evaluation of the treatment design. Improvements are shown through on-site analysis of treatment data and evaluation of production results.
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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.