bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shallow, High-Gravity Steamflood Economics Improved by New Application of High-Temperature Scale Inhibitor
Authors: Doll T. E. , Tyler M. L. , Dutton R. E. 
Published: December 2007

Abstract
The Shannon Reservoir at the Naval Petroleum Reserve No. 3, Natrona County, Wyoming, has some six years of Thermal Steam EOR history and has been expanded to six patterns with four 50 MMBTU/hr natural gas fired steam generators in operation.
During Pilot Steam Flood operations, scale formation at producing wellbores and tubulars became excessive. One pulling unit was employed full-time to mechanically cleanout tubulars and replace scaled pumps in 21 original Pilot producers. Acid Cleanouts and scale inhibitor squeeze jobs were expensive and short lived.
Due to planned fieldwide expansion of the Steamflood Pilot, the magnitude of costs associated with production side scale treatment would adversely impact project economics. A means to inhibit scale formation insitu from the injection to production wellbore was investigated.
Based on scale inhibitor application in steam generator tubulars in California, a successful chemical formulation was known to be available. Research determined that the product could be injected with the softened generator feed water and remain in the liquid phase of the injected steam. Sufficient residual was expected to be seen at the producing wellbore to prevent scale formation. A new analytical method had recently been developed to allow measurement of the chemical residual in the produced water. The chemical formulation had not been used in this type of application prior to use at NPR-3.
This paper details the successful application of scale inhibitor injected in the steam generator feed water, transported through the reservoir in sufficient concentration to inhibit scale and to provide measurable residual for confirmation. The economic feasibility is shown to be dramatic with long term reduction in pulling costs, elimination of ineffective acid cleanouts and scale squeezes, and minimal chemical cost to maintain residual at producing wellbores.
Delayed Borate Crosslinked Fluids Minimize Pipe Friction Pressure
Authors: Tan H. C. , Wesselowski K. S. , Willingham J. D. 
Published: December 2007

ABSTRACT
Borate-crosslinked fluids have increased in usage for fracturing treatments in recent years because of their low cost and low damage potential to formations. Until recently, most applications have been in shallow wells below 200°F because of high friction pressures and relatively low thermal stability. Recent advances in borate fluid chemistry have resulted in new techniques to minimize pumping pressure through the use of chemically delayed borate crosslinking agent.
Ability to minimize friction pressure with delayed borate crosslinker has reduced treatment cost and extended the application of borate-crosslinked fluids in deeper wells with higher bottomhole temperature (to 300°F). Laboratory and field data have been gathered to investigate the effects of fluid parameters on the friction behavior of the delayed borate-crosslinked fluid.
The laboratory experiments were performed with a recirculation flow loop to simulate field conditions. The field test was performed in a vertical wellbore. Measurements were made with three bottomhole memory gauges installed at various depths.
This paper presents friction pressure correlations derived from laboratory and field data for calculating realtime bottomhole treating pressure on-site to enhance the fracturing treatment analysis. Case histories are used to demonstrate the accuracy in friction pressure prediction for delayed borate-crosslinked fluids using the correlations presented in this paper. A method is also presented for field application of the friction pressure correlations provided in this paper.
High-Rate Refracturing: Optimization and Performance in a CO2 Flood
Authors: Hejl K. A. 
Published: December 2007

ABSTRACT
This paper presents the methodology used to optimize high rate refracturing treatments in a massive sandstone reservoir and associated incremental production response in a carbon dioxide (CO2) flood. Fracturing at high rates (70 to 100 bbl/min) using 10 lb/gal sand concentrations is necessary to fracture 700 ft of gross interval with 250 ft to 300 ft of net pay from six producing horizons.
Optimization of the work process reduced workover costs, fracturing costs, and contamination of the reservoir by fracturing additives and fluids. After the workover procedure was streamlined, fracture fluid additives and volumes for the pad, ramp, and final sand stage were examined.
It was hypothesized that fracturing in the area of the reservoir flooded with CO2 would accelerate CO2 breakthrough problems, causing increased CO2 production. Refracturing has increased the produced processing rate in the CO2 area of the reservoir, with little or no increase in CO2 gas production. Refracturing bypassed near well bore damage caused by barium sulfate scale and asphaltene precipitation associated with the CO2 miscible flood. Incremental oil response attributed with refracturing for the full field and CO2 flooded areas since March 1990 has averaged 52 and 58 BOPD, respectively, on a total of 85 wells.
The Effects of Mechanical Properties and Selection of Completion Interval Upon the Created and Propped Fracture Dimensions in Layered Reservoirs
Authors: Rahim Zillur , Holditch S. A. 
Published: December 2007

ABSTRACT
With the use of well log data and stress tests, reservoirs can be characterized by layers with different values of porosity, permeability, in-situ stress, Young’s modulus, and fracture toughness.1,2 These fluid flow and mechanical properties dictate not only the height, length, and width of a created fracture, but also affect the distribution of proppant in the fracture. Also, the location of the perforated interval in a layered reservoir plays an important role in the overall propped fracture dimensions.
We have developed a finite-difference, hydraulic fracture treatment simulator that computes fracture dimensions in a layered reservoir.3 Each layer can have different mechanical properties. The model allows initiation of the fracture in multiple producing intervals simultaneously. In this paper, we have used this model to illustrate the effects of mechanical properties on fracture dimensions and proppant transport profiles. In reservoirs with multiple producing zones, we have generated examples where the fracture is initiated in one or several intervals simultaneously, so that we can illustrate the effects of perforation placement upon the distribution of proppant within the fracture. These examples illustrate that the location of the perforations can substantially affect the final proppant profile. We have then taken the propped fracture geometry and used a single-phase finite-difference reservoir simulator to show the production increase and long-term production performance for the different scenarios.
A New and Improved Material Balance Equation for Retrograde Gas Condensate Reservoirs - Part I
Authors: Alvarado Gus , Le Blanc J. L. , Farshad F. 
Published: December 2007

ABSTRACT
A new and improved material balance method by which the original dry gas in place and the original condensate in place can be calculated for a retrograde gas condensate reservoir has been formulated.
This new MBE is a result of theoretical research that is validated using experimental data. Ultimate validation of the new MBE can be made with field cases, and after a laboratory Bc procedure is established.
The new MBE requires a modified PVT procedure to determine the condensate formation volume factor, Bc as introduced here. This variable is currently not in use in the industry and hence is not being measured in current PVT lab procedures.
A basic assumption in the new MBE is that no reservoir condensate is produced. Additionally, the new MBE assumes normal pressure, volumetric conditions, and existence of the reservoir at the dew point. Modifications to accommodate water influx and rock and water compressibility were made to the basic equations after validation.
Pressure Compartments in the Powder River Basin
Authors: Iverson W. P. , Martinsen R. S. , Surdam R. C. 
Published: December 2007

ABSTRACT
The Powder River Basin of northeastern Wyoming contains numerous subsurface pressure anomalies, both above and below normal hydrostatic. A study of approximately 5000 drill-stem-tests (DST’s) from the Powder River Basin reveals the geographic distribution of pressure compartments. The abnormally high pressure compartments within the Muddy Sandstone are selected initially for detailed analysis. Over-pressure in the Muddy pressure compartments is approximately 2000 psi over normal hydrostatic. Lithologie units surrounding a pressure compartment are sampled and measured for threshold displacement pressure with Mercury injection techniques. The seals surrounding the pressure compartment are not impermeable rocks; rather, they are capillary seals due to anomalously high displacement pressure in isolated portions of the Muddy Sandstone. These zones of high displacement pressure appear to correlate with unconformities within the Muddy Sandstone. This model of pressure compartmentalization is in marked contrast to Gulf Coast type models where overpressured aquifers are a result of disequilibrium compaction. Rocky Mountain pressure compartments require more effective sealing, as provided by capillarity and low-permeability rocks.
Simulation and Economics of Coalbed Methane Production in the Powder River Basin
Authors: Reid G. W. , Towler B. F. , Harris H. G. 
Published: December 2007

ABSTRACT
Coalbed methane has emerged as a significant resource for natural gas production in the United States, with estimates of gas-in-place of 400 trillion cubic feet. In Wyoming the largest coalbed methane resources occur in the Greater Green River, Powder River, and Wind River Basins. Very little of this gas has been exploited. This paper examines the potential of coalbed methane production in the Powder River basin by history matching early production from five gas wells in the Rawhide Butte field using a commercially available coalbed methane simulator, COALGAS. Sensitivity studies showed the most important parameters for establishing production were permeability, initial desorption pressure and drainage area. Langmuir constants, desorption time, porosity, well-bore diameter and skin were comparatively less important for long term production. An economic analysis showed that, based on current capital and operating costs obtained from industrial companies, the development of coalbed methane in the Powder River Basin may be economic if the gas sales price is greater than approximately $1/Mscf.
Deviation of Horizontal Well Interference Testing From the Exponential Integral Solution
Authors: Malekzadeh Dariush 
Published: December 2007

ABSTRACT
Interference tests provide valuable information about reservoir characteristics such as areal average transmissivity, storativity, and degree of communication between wells. Due to the larger radius of influence and larger contact area of a horizontal well with the formation than its vertical counterpart, the transmissivity and storativity obtained from interference testing of horizontal wells would be much more representative of the formation than the ones obtained from interference testing of vertical wells.
This paper provides the dimensionless pressure drop and dimensionless pressure derivative type curves for interference testing of horizontal wells and the appropriate equations to be used in conjunction with the type curves in order to determine transmissivity and storativity from field data. Solutions were also obtained for interference testing between horizontal and vertical wells. The deviation of this solution from the exponential integral solution is explained. Dimensionless time and dimensionless distance criteria is established for a particular set of dimensionless parameters to explain this deviation. Guidelines are given for interference test design.
Effect of Afterflow on the Analysis of Pressure Buildup Data From Solution-Gas-Drive Reservoirs
Authors: Hatzignatiou D. G. 
Published: December 2007

ABSTRACT
This work investigates the effect of wellbore storage on the analysis of pressure buildup data obtained in a solution-gas-drive reservoir. All results assume radial flow to a single well draining a solution-gas-drive reservoir with the initial reservoir pressure equal to the initial bubble-point pressure. Although connate water is present, the water is immobile and therefore during production only oil and gas flow within the reservoir. Wellbore storage effects are incorporated by specifying a sandface oil flow rate which during shut-in decreases exponentially from a stabilized constant value of the surface oil flow rate at the time of shut-in to zero. Based on a superposition equation new computational equations for computing effective oil and gas permeabilities as pointwise functions of pressure from the measured values of the shut-in wellbore pressure are presented. The computational equations require that the sandface oil flow rate be measured and incorporated into the analysis. By combining the computed effective permeability versus pressure relation with the oil saturation versus pressure results computed from the material balance equation, one can approximately construct the effective oil and gas permeabilities as functions of oil saturation. It is also shown that a semilog plot of shut-in pressure-squared versus Horner time represents a viable method for obtaining estimates of the mechanical skin factor and the effective oil permeability at the final value of shut-in wellbore pressure.
Clay Removal and Cut-Point Curve Analyses of a One-Step Solids Control Equipment
Authors: Malekzadeh Dariush , Hayatdavoudi A. , Ghalambor A. , Okoye C. U. 
Published: December 2007

ABSTRACT
The objective of this paper is to evaluate the performance of a One-Step Solids Control Equipment (OSSCE) based on the actual field data. The material balance technique was used to achieve this objective. The data obtained consisted of density, volume flow rate, solids content, and size distribution of each flow stream of OSSCE. The cost-effectiveness of using OSSCE as compared to mud cleaners was investigated using the actual field data obtained on the same mud run through the two equipment. In addition, the cut point curve for each equipment was obtained.
The results indicated that the cost of using mud cleaner on the mud sample analyzed is about 4.5 times higher than that of using OSSCE. This is due to the fact that the mud cleaner discarded only 1.7 times more low gravity solids than weight material while OSSCE discarded 4 times more low gravity solids than weight material. About 31% of Chlorite that entered OSSCE was discarded by concentric discharge and screen overflow discharge. This high percent by volume of Chlorite discarded is attributed to the high amount of flocculation of Chlorite particles. The lowest percent by volume of clay type discarded belongs to Kaolinite (3%), which is due to the lesser amount of flocculation by this clay type. Finally, the results indicated that the cut point curve will shift to the left as the volume flow rate of screen overflow discharge increases, resulting in sharper separation or lower d50.
Safety and Shutdown Systems for Offshore Facilities
Authors: Heraiba F. A. , Rahman O. A. 
Published: December 2007

ABSTRACT
ZADCO operates three offshore fields which comprise crude oil production facilities and process plants. The facilities present potential hazards in handling flammable hydrocarbon liquids and vapours.
Comprehensive safety philosophy was employed to minimize the associated risks and sophisticated detection, and control systems based on Programmable Controllers were installed.
This paper outlines the approach adopted by ZADCO and describes the installed safety systems. The paper presents the experience gained during the operations and provides recommendations for similar installations.
Health Care in Developing Countries
Authors: Dawson Donald G. 
Published: December 2007

Abstract
Each country presents its own set of challenges when a health care programme is to be developed. It may include malaria in Africa, snakes and insects in Myanmar, rabies or gun shot wounds in the outback of Colombia, sexually transmitted diseases in Thailand, or the health hazards of poor hygiene anywhere. What I wish to do today is to outline the development of a health care programme required in a developing country through the various phases of exploration work, to hopefully the final long awaited production of oil and gas in a sophisticated modem plant.
The Effect Of Low-Water-Loss Additives, Squeeze Pressure, And Formation Permeability On The Dehydration Rate Of A Squeeze Cementing Slurry
Authors: Hook F.E. , Ernst E.A. 
Published: December 2007

The Effect of Low-Water-Loss Additives, Squeeze Pressure, and Formation Permeability on the Dehydration Pressure, and Formation Permeability on the Dehydration Rate of a Squeeze Cementing Slurry
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.

Abstract
In an effort to improve the success ratios of squeeze cement jobs, recent studies were made of the effects of fluid-loss control additives, differential pressures, formation permeability, and placement techniques on the performance of squeeze cement slurries. The studies showed that the rate of filter cake build-up is the most important factor to be considered in squeeze cementing. They further showed that this rate is a function of the variables listed and can be calculated by Darcy's equation for flow of liquids through a permeable media. Use of Darcy's equation showed that fluid-loss additives currently in use function by reducing the permeability of the filter cake. This slows down the rate at which filtrate can be forced through the filter cake and controls the dehydration rate of the slurry.
This paper presents data relating the effects of the various factors on the dehydration rate of the slurry, and shows how a knowledge of well conditions and mechanisms of filter cake build up, along with good control over slurry properties can provide an appreciable improvement in the success ratios of squeeze cementing operations.

GENERAL DISCUSSION
Squeeze cementing is a remedial cementing technique which has always been difficult. Since the introduction of low-water-loss additives for cement; however, the success ratio has consistently increased. These additives have made possible many placement techniques which previously would have been impossible. An understanding of the factors which influence water loss and filter cake formation is a great aid in the selection of the optimum slurry properties and placement techniques.
In order to attain a successful squeeze job, it is necessary to properly place the cement slurry. The slurry consists of finely divided particles mixed with enough water to contact all of the particles. As the slurry is forced against a permeable formation, particles will be filtered out on the face of the formation to form a filter cake. In most squeeze jobs, it is desirable to form this filter cake—but it is necessary to control its growth rate.
Drilling Manpower Planning: Using a Systems Dynamics Approach
Authors: Brett J. F. , McCuish J. D. , Oates K. W. 
Published: December 2007

Abstract
This paper summarizes the results of a study testing the idea that "System Dynamics" techniques can be applied to gauging the effects of manpower application on drilling performance. The techniques discussed here are traditional engineering modelling techniques that have lately been applied to management2,3,4,5 and petroleum problems,1 and hold promise of broad applicability in drilling management. The specific problem of manpower planning was chosen as a test case for other drilling applications.
The concept behind these techniques is to quantify the behavior of the system describing the specific problem at hand. In this way, the consequences of assumptions about a process are explicitly tested. The manpower planning model described here is the result of an iterative process, whereby the model's basic form and predictions were compared with actual results. The scope, purpose, and benefits are described on the following pages. The study showed that System Dynamics techniques are useful tools for planning drilling manpower requirements.
Erodability of Partially Dehydrated Gelled Drilling Fluid and Filter Cake
Authors: Ravi K. M. , Beirute R. M. , Covington R. L. 
Published: December 2007

ABSTRACTPartially dehydrated-gelled drilling fluid and filter cake must be displaced from the wellbore annulus to achieve a successful primary cement job. A term ‘Erodability of drilling fluid’ is defined in this paper and was calculated from measured parameters in a large-scale test model. Differential pressures were measured in the annular space between the casing and a man-made, permeable formation and also inside the casing. Three different drilling fluids used in typical field operations were tested. Each drilling fluid was tested over a period of four days. Experimental data on erodability of drilling fluid filter cake is presented as a function of time, flow rate, and aging. A mechanism is proposed for the erosion of partially dehydrated-gelled drilling fluid and filter cake. Recommendations are given to improve the removal of partially dehydrated-gelled drilling fluid and filter cake and thus achieve a successful primary cement job in field operations.
Real-Time Well Control Advisor
Authors: Milner G. M. 
Published: December 2007

Abstract
A summary of the design, and design rationale, for a software Well Site Advisor (WSA) tool to prompt and train drilling personnel in taking well control actions is presented. Key features of the WSA are: (1) a seven state Kaiman filter to estimate (track) and predict well and influx parameters during well control. Estimated and predicted parameters include bottom hole pressure, volume of influx gas, volume of influx liquid, influx position, influx distribution, influx velocity (top and bottom), and expected future pressures and volumes; (2) CuSum analysis of errors between predicted and measured pressures and volumes to detect meaningful deviations indicating possible problems; (3) automated pattern recognition or classification of data trends; (4) expert system processing to finalize the diagnosis of problems and provide advice; and (5) graphical user interface and efficient coding to provide rapid data entry, interpretation, and processing.
The WSA system is the final product of DEA-49, a thirty-month study funded by the Drilling Engineers Association, to develop a real-time well control advisor tool. Prior prediction systems have usually been designed for well planning functions or post-kick control analysis and were not capable of responding to events as they occur during kick control operations. This system provides real-time computer capability to accurately process, predict, and interpret kick control surface measurements (e.g., drill pipe pressure, casing pressure, pit gain, drill string weight, and pump strokes per minute) so that automated problem detection, diagnosis, and advice are possible during kick control.
Test results, including simulations, test well data, and actual kicks while drilling, are very promising and are discussed.