bluuebunny/crossref_metadata_2025_split huggingface dataset:
Method for Improving Hydrocarbon/Water Ratios in Producing Wells
Authors: Dunlap D. D. , Boles J. L. , Novotny R. J. 
Published: December 2007

ABSTRACT
Production of unwanted water has consistently burdened the industry since the costs of lifting, separating, and disposing of produced water make oil and gas production less profitable. Previous methods for reducing water production have involved the sequential pumping of two or more materials to form plugs within the formation to control water flow. These materials have been neither effective nor selective in-reducing only the flow of water.
The recent introduction of new water control chemicals, which are designed to, reduce the flow of water while not effecting hydrocarbon flow have experienced limited success. One reason for the minimal success rate has been the inability of these polymers to withstand shear. In addition, poor candidate selection has created a high volume of unsuccessful treatments, causing operators to shy away from their use.
A selective, one component system using a new amphoteric polymeric material (APM) has been developed which has the ability to reduce the effective permeability to water while retaining the formation permeability to oil or gas.
In addition a candidate selection technique used to predict the likelihood of success of a water control treatment is presented.
Productivity Decline in Gravel Packed Wells After Acidizing
Authors: McLeod H. O. 
Published: December 2007

ABSTRACT
The current interpretation of gravel pack productivity decline seems to focus on dispersion and plugging with formation fines, especially after acidizing. This paper presents an alternate explanation. Gravel may be flushed from perforations during acidizing into acidized formation voids, gravel may move into acidized gravel pack voids in the screen-casing annulus during production start-up, or tunnel voids may have existed prior to acidizing as a result of poor gravel placement during gravel pack execution. Production start-up rate controls how formation sand enters partially filled voids after acidizing. A controlled production rate allows formation sand to enter the tunnel above the gravel so that a more conductive parallel alignment of sand and gravel in the tunnel is created.
Underbalanced Perforating in a Closed System
Authors: Seanard K. C. 
Published: December 2007

ABSTRACT
Several recent papers have been written expounding the use of tubing conveyed perforating as, a completion technique. (See Ref. 1,2) These papers propose the use of underbalanced perforating to remove perforating damage. This paper will present a recommended method of perforating underbalanced in a closed system. Perforating in this manner allows the use of high pressure differentials to surge the perforations while at the same time limiting influx into the wellbore and allowing control of the well.
Polymer Shear Mixer: A Device for Improving the Quality of Polymer Viscosified Brines
Authors: Ashton J. P. , Nix C. A. 
Published: December 2007

ABSTRACT
A shear apparatus has been developed to improve the quality of polymer viscosified brines. Application of the device to mix the polymer into the brine results in a viscous brine that can be cost effectively filtered. The rheological properties of the fluid remain virtually unaltered when compared to similar brines mixed by conventional methods.
Development of Fuyu Fractured Sandstone Reservoirs by Water Injection
Authors: Chen Yanzheng 
Published: December 2007

ABSTRACT
The Fuyu fractured sandstone reservoir is characterized by low permeability and medium high crude viscosity. There is insufficient natural energy because of its shallow depth of burial. The field was put into development in 1970 under solution gas drive. Water injection was started in 1973 and an overall adjustment of the development program was made in 1982.
The following methods have been used successfully according to the geologic features of the field as well as the problems occurring during development: To supply more energy by active water injection.The rapid decline of the production and reservoir pressure under solution gas drive has been stopped and gradually restored.Well-developed vertical fractures and horizontal bedding in the overlying shales result in a good permeable zone. Under high injection pressures, water runs from the reservoir formation into these layers and causes swelling of the clay minerals in them, so that a lot of casing damage occured with a serious effect on the production of the field. Thus it is important to control injection pressure and to take comprehensive measures to eliminate the casing damage. Good results have been obtained.The data from non-invasion cores and from newly drilled wells have been used to study the status of water flooding, the reserves affected by current status development program and the distribution of the remaining oil in the reservior. Based on such a study, the adjustment wells are located in the areas where the majority of the remaining oil exists. The zones with medium and low Water cut have been perforated for production, thus more reserves will be put into water drive production.According to the characteristics of fracture development in the reservoir, a linear injection pattern has been used to restore the reservoir pressure and to prevent water channeling through fractures. Good results have been achieved.
Development by Waterflooding of Maxi Deep Reservoir with Low Permeability
Authors: Wang Zhizhong , Zhang Xuyuan 
Published: December 2007

ABSTRACT
Maxi oilfield – a deep seated reservoir, located in the central part of North Dagang structural belt of Huanghua Depression, Is an Integrated dome anticline with major axis extending in a NE direction, being steep in the north and gentle in the south. The structure covers an area of 11 square kilometers with a vertical closure of 130 meters. The main pay zones are Ban II and III, T1 of paleogene, being a suite of bar sand and beach sand deposits of deep littoral facies. The depth of burial of the reservoir is 4,000 meters with relatively poor physical properties. The porosity is 13.3% and permeability is 13.6 md. It is of argillaceous cementation with a fair sorting. Rock compaction and secondary growth are obvious.
The distribution of oil, gas and water are mainly controlled by the structure. The oil-water contact is quite clear, being 3,900 meters in Ban II and 3,970 meters in Ban III. The crude property is good with low specific gravity of stock tank crude (with an average value of 0.8408) and low viscosity (6.2 cp/50°C on an average). The asphaltene content is low (4.98 percent on an average). The reservoir temperature is high (149°C). The presssure coefficient is also high (1.473/10m) with a large pressure difference between reservoir and saturation pressure (186 atm.). The underground viscosity of crude is abnormally low (0.38 cp). Therefore, it is a structural reservoir with an abnormally high pressure, low permeability and is undersaturation.
Exploration of this field began in 1965. In 1978, commercial oil flow was encountered and put into development with a 500m 5-spot well pattern in 1980. By the end of 1981, it was put on stream. Its recovery rate has been kept high during the four-year period of production. A series of development techniques have been used for deep-seated reservoir, such as protection of the reservoir from mud contamination, through tubing perforation under negative pressure differential, water injection under high pressure (400 atm), development through separated technique, deep pentrated fracturing, and a closed oil and gas gathering and transportation system, etc. thus achieving good oilfield development results. There were 21 oil wells and 5 injection wells by the end of 1984. The daily production was 473 tons and cumulative production reached 780,000 tons. The overall water cut was 6.5%. Daily injection of water was 613 m3 in five injection wells and the cumulative water injected reached 721,000 m3. The production capacity of oil wells was quite good and waterflooding was carried out normally.
A Study on Some Problems in the Calculations of Corrosion Fatigue Life of Structural Members of an Offshore Platform
Authors: Fang Huacan , Dong Shouping , Chen Zhenxin 
Published: December 2007

ABSTRACT
This paper presents the results of research and tests on some problems involved in calculations of corrosion fatigue life of structural members of a platform, using the theory and method of fracture mechanics.
According to random vibration theory, the method and a programme for making the random sea wave spectrum and the method for calculating the transfer function of a structural member of a platform are given. The method and programme for composing the spectrum of random stress amplitudes by random sea wave spectrum and transfer function is proposed; finally, for counting the load cycles in estimating the fatigue life, a new method of cycle counting is proposed using two parameters of stress ratio and stress amplitude directly from the random stress spectrum.
In order to evaluate the fatigue life, experiments on constant amplitude and random fatigue crack growth rate have been carried out; the Paris' formula has been modified; a programme for the experimental data processing has been given; and the method and an example for calculating residual corrosion fatigue life of the structural member of a platform, based on fatigue damage criteria dadn in terms of the crack growth rate are given, and is illustrated by a sample calculation
Investigation on the Applications of Statistical Formation Drillability
Authors: Yin Hongjin 
Published: December 2007

ABSTRACT
An equal probability correlation of bit types and formation drillability grades has been established with experimental and statistical methods. The variation of drillability with depth has been studied. The empirical equations of drillability varying with depth is checked with a parametric equation of drilling rate. Useful information of macroscopic formation drillability can be derived from statistical analysis of abundant individual microbit drillability testing results.
A Study of Sulfide Scavenger
Authors: Chen Chuanlian , Huang Wenqin 
Published: December 2007

ABSTRACT
A sulfide scavenger CS 6-1 has been developed to protect the drilling tool from sulfide stress cracking, electrochemical corrosion and corrosion fatigue. The desulfurization efficiency and corrosion inhibition rate of the scavenger were measured for laboratory and field muds. Its desulfurization efficiency exceeded 98% and the corrosion inhibition rate was up to 70-90%. The addition of an appropriate amount of CS 6-1 doesn't affect the mud characteristics. Field tests have shown that the desulfurization efficiency of CS 6-1 in alkaline muds is better than that of sponge iron and Milgard scavengers.
Heat Flow During Steam Injection Into a Fractured Carbonate Reservoir
Authors: Dreher K. D. , Kenyon D. E. , Iwere F. O. 
Published: December 2007

Summary
Steam injection into fractured carbonates has been examined in the laboratory and with a fully implicit reservoir simulator. These studies showed that significant oil can be recovered from matrix elements when hot water or steam is injected into fractures. Heat is rapidly replenished to fractures and heat conduction into the matrix plays a major role in matrix heating with a resulting increase in the rate of oil release. At steam temperatures carbonates decompose to produce a significant amount of CO2 which further enhances the recovery rate.
Carbonate disks were flooded in the laboratory with hot water and steam. Oil recovery from competent as well as fractured disks increased as injection temperature increased. Oil recovery from fractured disks approached 30% 0IP at 200°F even though pressure differentials were small. In other experiments, CO2 con-centration in effluent gas was determined. One mole of CO2 was produced for each mole of H2O injected at steam temperatures.
Reservoir simulations were accomplished using two kinds of porosity/permeability grid blocks. Fracture grid blocks were continuous from injection to production wells and accounted for less than 0.5% of the total reservoir volume. Oil recovery and water/oil ratios were dependent on matrix grid block size, steam Injection rate, initial saturations and distributions, and CO2 generation. Oil recovery increased with in creasing steam injection rates, however, water/oil ratios were high. These results show that there is an optimum steam injection rate for a specified reservoir volume and matrix grid block size. The rate of heat conduction from fracture to matrix is the controlling factor.
Measurement of Steam Quality, Mass Flow Rate, and Enthalpy Delivery Rate Using Combined Neutron Densitometer and Nozzle
Authors: Woiceshyn G. E. , Yuen P. S. , John H. , Manzano-Ruis J. J. 
Published: December 2007

Abstract
Accurate measurement of steam quality and enthalpy delivery rate at the wellhead is required for efficient operation and reliable evaluation of enhanced recovery projects that utilize steam injection. Steam distribution through manifolds and tees can lead to uneven splitting and a wide variation of steam quality and enthalpy delivery rate for different wells fed from the same boiler. A field-grade densitometer, which is based on the principle of thermal neutron transmission, has been developed and tested for measurement of steam quality at the wellhead. The meter is non-intrusive, portable, robust, easy to operate, safe for field use and accurate. By combining the meter with a flow measuring device, such as a flow nozzle, accurate measurements of steam quality, mass flow rate and enthalpy delivery rate at the wellhead are possible.
This paper describes the densitometer's principle of operation and results from recent calibration tests conducted over a wide range of field conditions.
Effect of Capillary Number on the Residual Saturation of a Three-Phase Micellar Solution
Authors: Delshad M. , Bhuyan D. , Pope G. A. , Lake L. W. 
Published: December 2007

Abstract
One of the most important physical relationships in a low interfacial tension IFT process is the capillary desaturation curve (CDC). The CDC is the relation between residual phase saturation and the ratio of viscous to local capillary forces (capillary number). Despite its importance, a complete set of experimental CDC for low IFT fluids has not been reported in the literature.
We report CDCs for a low IFT two-and three-phase brine/oil/surfactant/alcohol mixture in Berea sandstone cores. These are the first CDCs reported for a three-phase micellar solution. There are six possible CDCs for three phase flow. We have measured (l)-residual oil to microemulsion, (2)-residual microemulsion to oil, (3)-residual brine to microemulsion, and (4) -residual microemulsion to brine. These CDCs have been measured by stepwise increases in flow rate at a fixed IFT of 0.7 μN/m. These data showed that the microemulsion phase is the most strongly trapped which implies that the microemulsion is the wetting phase--even more wetting than the excess brine.
We also include CDC data for a two-phase (brine/oil/alcohol) mixture of fresh and Dri-Film treated Berea sandstone. The data in fresh core are in good agreement with the micellar CDC data.
Continuous displacements of radioactive tracers have also been run during these steady-state, single-phase flows. The tracer analysis provided essential information on both phase saturations and dispersivities.
The single-phase dispersion coefficients for tracer in oil, brine, and microemulsion phases showed the well-known increase with phase frontal velocity that is typical for single-phase flow of brine reported in literature. No values for oil or microemulsion have been previously reported. The tracer dispersivities showed little dependence on phase saturation.
High-Pressure Combustion Tube Tests
Authors: Prasad R. S. , Slater J. A. 
Published: December 2007

ABSTRACT
High pressure air fireflooding may have some benefits hitherto not observed at lower pressures. Combustion tube tests were conducted at pressures approaching 3,000 psi. Special start-up procedures were used, especially for the wet burns, to make the testing representative and also minimize the transient effects. The tests indicated: Immiscible displacement of oil by carbon dioxide is an important mechanism at these pressures.The heat-scavenging ability of the water injected along with the air is, as expected, still appreciable at these pressures.
Comparison of Recovery and Economics for Oxygen and Air Fireflood in Canadian Heavy Oil Areas
Authors: Dugdale P. J. 
Published: December 2007

Abstract
The heavy oil pools of Alberta and Saskatchewan can be grouped into four reservoir types: Lloydminster, Wainwright, Basal Quartz and Bakken.
This study reviews briefly the recovery attainable in these reservoir by secondary and non-fireflood processes, and then evaluates in situ combustion using both oxygen and air in dry and wet fire-floods. Recent studies by a national energy agency have shown that fireflood is the best enhanced oil recovery process that can be used in heavy oil reservoirs, with anticipated recoveries of 30% of the original oil in place. The paper reports the computed recoveries using the Tejas, Nelson-McNeil, Fassihi and Brigham methods and then presents an incremental recovery correlation due to the immiscible CO2 flood established ahead of the oxygen firefront.
The experimental evaluation of key fireflood parameters is examined and compared to those predicted by correlations available in the literature. Air/oxygen requirements, fuel laydown and rate of firefront advance, as well as oxidant injectivity are discussed; recommendations are made on the laboratory and field testing needed prior to implementation of in situ combustion.
An economic comparison of both air and oxygen firefloods, which considers the recoveries and field costs for the two processes, has been carried out for a demonstration pilot in a Wainwright type field.
A Study of Caustic Consumption by Clays
Authors: Huang L. , Yang P. , Qin T. 
Published: December 2007

ABSTRACT
The reactions of alkaline with clay minerals in reservoir rocks have been investigated under static conditions.
With the help of the titration, the determinations of the irreversible chemical kinetics of the reaction of alkaline with 3 kinds of clay minerals and quartz were carried out at 60°C. High concentration sodium hydroxide and orthosilicate were used in these treatments for a time period as long as 1000 hours. The supernatants were analyzed for hydroxide, (Si), (Al) etc. and precipitated solid parts at different time periods were analyzed by X-ray differaction and other methods. The results show that the irreversible consumption of sodium hydroxide is the highest on montmorillonite and it is not a simple reaction. The consumption is very fast at first and slow down gradually. The alkali consumption can not be described by a single first-order reaction. The reaction is associated with the formation of new minerals which are mostly zeolites and the consumption of dissolved (Al) in later reaction, other than (Si), was observed.
On the other hand, fast reversible alkaline consumption by ion exchange was observed at room temperature accompanied with the reaction controlled by chemical kinetics. H/Na exchange adsorption isotherms are Langmuir type in shape. The reversible alkali consumption is also the highest on montmorillonite. The test results show that it can be decreased by using a high salinity preflush and a subsequent low salinity caustic solution injection.
A Method To Convert Multiple-Shot Section Openhole Completions Into Cased-Hole Completions With Zonal Isolation
Authors: Darr C. D. K. , Brown E. K. , Murphey J. R. 
Published: December 2007

ABSTRACT
A method to convert multiple shot section open hole completions into cased hole completions has been developed and tested. This method provides zonal isolation between shot sections thus helping prevent injection fluid loss to non-pay intervals. The process, called "Puddle-Pack", involves formulating a permeable resin fill material and placing the material in the shot open hole to fill the large voids. The excess material is then drilled out and underreamed to allow a liner to be run and cemented in place. This paper details the necessity for the development of the process, design requirements, laboratory pretesting of the sand-resin mixture, remedial procedures, data demonstrating zonal isolation and profile improvement, and economic advantages of converting these wells to cased hole completions.
The Value of CO2 to Today's Producer
Authors: Jankowski D. J. , Wolsky A. M. 
Published: December 2007

ABSTRACT
The cost of carbon dioxide, CO2, is the principal component of the cost of miscible flooding for enhanced oil recovery, EOR. This paper presents an engineering-economic framework that shows how to estimate the amount an EOR project can afford to pay for delivered CO2, This amount (here called "permissible cost"), depends on many factors, both geologic and financial. We show how the effects of these factors combine to produce the permissible cost, with the emphasis on its sensitivity to flooding efficiency, oil price, and internal rate of return. We use parameters given in the National Petroleum Council's Enhanced Oil Recovery reports (1976 and 1984) to illustrate the results for two hypothetical reservoirs. These results display variability that should be expected from different fields.
An Economic Evaluation of Waterflood Infill Drilling in Nine Texas Waterflood Units
Authors: Reviere R. H. , Wu C. H. 
Published: December 2007

ABSTRACT
This paper examines the profitability of past waterflood infill drilling programs. The project data is from the Texas Railroad Commission files, and includes large carbonate and sandstone reservoirs such as the Wasson (San Andres) Field and the Big Wells (San Miguel) Field. All of the reservoirs were subject of intensive reservoir engineering and geologic study by the oil companies prior to initiation of the infill drilling project. The permeability of the reservoirs averages 8.8 md and ranges from .65 md to 27 md. The porosity averages 10% and ranges from 7% to 18.6%. The depths range from 1220 to 1525 meters with the deepest at 2130 meters.
Because of the large capital cost required for drilling and operating additional wells, it was not clear whether the infill drilling programs had recovered enough additional oil to be good investments. In spite of the variability of external factors such as the cost of wells and price of oil, all of the projects studied obtained at least an acceptable economic return, the average discounted profit to investment ratio was 2.0, and the average incremental oil per well was 15 thousand cubic meters. Most of the calculated rates of return exceeded 30%. The net present value at 15% after taxes ranged from $580,000 to $32 million dollars. Thus these waterflood infill drilling projects have generally been very successful.