bluuebunny/crossref_metadata_2025_split huggingface dataset:
Economics of In-Depth Polymer Gel Processes
Authors: Norman C. A. , Smith J. E. , Thompson R. S. 
Published: December 2007

Abstract
Traditionally, polymers have been used in waterfloods to address an adverse mobility ratio. However, polymer gel processes can also reduce permeability variation in heterogeneous reservoirs, resulting in a more uniform flood front and improved recovery efficiency. Forecasting the economics of a polymer process and selection of the appropriate polymer technology are fundamental to project success. This report offers a methodology for assessing the economic risk of two variables critical to waterflood performance: injection efficiency and permeability variation. Also, an economic model that compares a conventional waterflood, a polymer enhanced waterflood and a waterflood utilizing colloidal dispersion gels (CDG's) demonstrates an objective approach to project selection.
Case History of Miscible Gas Flooding in the Powder River Basin North Buck Draw Unit
Authors: Fulco G. J. 
Published: December 2007

Abstract
The North Buck Draw Unit (NBDU) produces volatile oil from the Dakota sandstone in the Powder River Basin. This high-pressure, miscible gas injection project is in its eleventh year of operation. The field has been under partial pressure maintenance since November 1997. Blowdown is scheduled in 1999.
Based on the performance and operating experience at NBDU, it is concluded that the Dakota Sand formation and its fluid properties in the deep Powder River Basin are favorable for miscible gas flooding. Horizontal drilling met with mixed results. WAG operations initiated in the latter part of the project life was successful in extending the life although the effect of injected water on ultimate recovery is still unknown. In addition to process understanding and reservoir and fluid characterization, continuous surveillance of performance is very important to the success of a project such as NBDU.
The project has outperformed original projections and has been very successful, technically and economically. The cumulative production of 22 MMB represents over 62% of the original oil-inplace (OOIP). Ultimate recovery will exceed 65% OOIP.
This paper documents all aspects of the field development, flood operations and performance.
A New Study Of Domestic Petroleum Profitability
Authors: Hubbell Robert O. , Derouen Gordon A. , Yee Raymond S. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

Abstract
Three case studies representing domestic petroleum investment situations currently of interest were examined for economic relationships. Multiple cash flow analyses were performed by a sophisticated computer program utilizing sensitivity analysis and user-directed algorithm modification via data input. Tax rules specified by the 1975 Tax Law were programmed and are included in this study. The results are presented as a series of figures demonstrating the dependence of profitability indicators on project variables. Cases investigated project variables. Cases investigated were: I, Domestic Onshore Dry Gas Development Case; II, Domestic Offshore (Federal Waters) Gas Prospect Bidding Case; and III, Domestic Onshore Oil Development Case.

Introduction
Currently the most unsettled functional area of the petroleum industry is economics. The period commencing several years ago and continuing today is one of nonpareil change, worldwide and nationally, in the economic constraints under which the American capitalistic petroleum industry exists. The interrelated factors of rapid inflation, ascending but unstable petroleum prices, increasing governmental tax and prices, increasing governmental tax and acquisition tendencies, and more difficult and expensive drilling operations have combined to require frequently hard investment decisions from managers or owners. The decision maker, in turn, demands from his staff or consultant the most reliable economic analysis possible under time and budget limitations. Such an assignment normally dictates utilization of the computer tool to perform swiftly and cheaply period-by-period perform swiftly and cheaply period-by-period cash flow analysis.
A New Technology in Potable Water Disinfection for Offshore Rigs
Authors: Nathan P. Regu 
Published: December 2007

Abstract
Disinfection of potable water aboard ships and oil rigs is presently accomplished through chlorination by feeding calcium hypochlorite solutions. This method has several drawbacks in terms of equipment operation, maintenance, reliability and safety. Recently developed equipment utilizes disposable filter cartridges containing bromine impregnated resin to feed predetermined amounts of bromine into the water system for disinfection. These bromination systems have been field tested and have been found to be safer, more reliable, and easier to maintain, and they provide a greater health safeguard aboard ships and rigs.

Introduction
While recognized as necessary for sustaining life, water has long been suspect as a vehicle for the transmission of many diseases to man. Yet it was not until just over 100 years ago that this pernicious role of water was confirmed. With definite evidence on hand, emergency treatment with hypochlorites became quite common during periods of epidemics and in 1904 the first attempt of continuous chlorination of a public water supply was initiated. With the development of facilities for feeding gaseous chlorine in 1912, chlorination of public water supplies has grown rapidly and has become routine in this country. The result has been dramatically low epidemic incidences during the last few decades.
Chlorination is practiced to disinfect a water supply, i.e., to kill pathogenic (disease causing) organisms, and thus prevent the spreading of pathogenic (disease causing) organisms, and thus prevent the spreading of water-borne diseases. However, besides killing organisms, chlorine also reacts and oxidizes a wide variety of other impurities in the water; particularly ammonia, iron, hydrogen sulfide, manganese, nitrites, and particularly ammonia, iron, hydrogen sulfide, manganese, nitrites, and organic compounds. Many such reactions are rapid and their demand for chlorine must be satisfied before chlorine becomes available to accomplish disinfection. Thus, the level of chlorine addition has to be in excess of the actual demand, allowing for a measurable chlorine residual to accomplish and indicate completion of the disinfection process.
Gaseous chlorine is toxic to man and is dangerous to handle, but adequate materials and methods have been developed for its use in public water supplies, where the process can be supervised by attending personnel. In small or private water systems where constant attention cannot be provided, gaseous chlorine is not used for disinfection.
Effect of Cyclic and In Situ Heating on the Absolute Permeabilities, Elastic Constants, and Electrical Resistivities of Rocks
Authors: Aktan T. , Ali S.M. Farouq 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

Abstract
An experimental study was conducted to determine the effects of cyclic and in situ heating on the Young's moduli, bulk moduli, Poisson's ratios, resistivities and Poisson's ratios, resistivities and permeabilities of Berea, Boise, California and Tennessee permeabilities of Berea, Boise, California and Tennessee sandstones.
Elastic moduli were calculated by measuring the longitudinal and shear wave transit times of the cores subjected to triaxial pressure. Samples were loaded to 5000 psi overburden pressure at 1000 psi increments, and the pressure at 1000 psi increments, and the confining pressure was kept at 60% of the overburden pressure.
Cyclic heating and cooling runs were carried out by placing the cores in steel core holders and heating them at 550 deg. F and 2000 psig pressure in a convection oven. Afterwards, pressure in a convection oven. Afterwards, the cores were placed into the triaxial cell to measure the longitudinal and shear wave transit times. In situ heating experiments were conducted by simultaneously heating the core to 300 deg. F in the triaxial cell and measuring the elastic wave transit times.
Permeabilities of dry and saturated cores were measured using the Ruska permeameter. Resistivities were calculated by determining the resistance of the 2% brine saturated sandstones by the aid of a Wheatstone bridge.
Longitudinal and shear wave velocities for the sandstones tested decreased as a result of microcracks formed during heating-cooling cycles to 550 F, and in turn, being dependent on the wave velocities, the Young's modulus, bulk moduli, and Poisson's ratios showed significant reductions. In the in situ heating experiments, the decreasing trend of the dynamic elastic constants was less pronounced than that observed in the cyclic heating experiments. Absolute permeabilities of the Berea and Boise sandstones showed progressive increases upon heating to 300 deg. and 500 deg. F, respectively, while the electrical resistivities of all four sandstones exhibited considerable reductions when heated to the same temperatures.

Introduction
A comprehensive study of a reservoir under thermal treatment warrants a knowledge of the temperature and pressure dependence of the petrophysical properties of the constituent petrophysical properties of the constituent reservoir rocks. In particular, the temperature dependence of the rock elastic moduli plays an important role in the analysis of the thermal stresses induced by the flow of hot fluids in porous rocks. porous rocks.
Effect of a Wetting Immobile Phase on Diffusion and Macroscopic Dispersion in Unconsolidated Porous Media
Authors: Verlaan M. L. , Dijkgraaf H. F. , van Kruijsdijk C.P.J. W. 
Published: December 2007

Abstract
The objective of this paper is to determine the effect of a wetting immobile phase (e.g. connate water) on the diffusion and macroscopic dispersion in homogeneous unconsolidated packs. We measured the effective dispersion coefficients of gases as a function of water saturation, pressure, and velocity in a laboratory set-up. The dispersion coefficients were 2 to 3 times higher than in the dry porous medium. This effect is also studied using a pore network model where the immobile phase blocks a fraction of the pores for fluid flow. A random walk through the network and counting cluster sizes both gave approximately the same results, which were in good agreement with the experimental data.
Interference Testing to Verify Drainage Strategy for a Large Offshore Development
Authors: Jensen Bjorn , Hjelleset Ellen Angelina , Larsen Leif 
Published: December 2007

Abstract
The paper presents plans, execution and results from a multirate interference test to verify drainage strategy for the large HPHT Smorbukk reservoir in the Aasgard field offshore Norway. The critical question being communication between oil producers and a planned updip line of gas injectors. A fractured oil well undergoing an extended well test to determine the long-time production behavior of fractured wells in a reservoir with a fluid system near critical conditions was the source of the interference data.
The interference test was planned with surface read-out (SRO) through accoustic signal transmission from the wellhead of the observation well to the active well platform. The SRO part of the test failed, but memory gauges for later retrieval were also installed in the well. The test ran from Nov. 96 to Jan. 97, with both pre and post fracturing production periods, but the gauges were left in the hole until the well was re-entered Sept. 98. During this period the gauges were exposed to temperatures near 160°C for nearly two years, but two of six gauges were still found to contain data consistent with their sampling scheme, with one gauge sampling data long enough to pick up the response from the post fracturing extended well test.
Use of NMR Logging for Formation Damage Prevention: Water-Flooding Case Study in Cañadón Seco, San Jorge Basin
Authors: Diaz Delia C. , Breda Eduardo , Minetto Carlos , Atlas Baker , Chen Songhua 
Published: December 2007

Abstract
Water flooding is a well-established secondary oil recovery technique used in many reservoirs around the world. A key issue involved in water flooding is the prevention of the invasion of solids, which may cause formation damage and, consequently, inhibit injection and cease production. To remove fine particles cost-effectively from the flooding fluid, it is necessary to determine the maximum size of the particles that can flow with the fluid without plugging the formation. Determination of the threshold particle size, however, is often very challenging.
In this paper, we report a successful water flood case study for San Jorge Basin reservoirs. Nuclear magnetic resonance log (MRIL [R]*) data were used to obtain the pore size distribution. Core NMR measurements were conducted to validate the T2 distributions derived from the MRIL logs. In addition, the same core samples were analyzed with conventional methods, including capillary pressure, SEM, thin section, and mineralogical analyses. Based on the MRIL log and core data, we were able to establish the correlation between the T2 distributions in the formation and the threshold solid particle size allowed in the injection water, which is important to prevent formation damage.
A critical step in the process is the accurate determination of T2 distribution. Different inversion techniques were used for data processing from which we found that the inversion with gamma-density functions is the most suitable for matching the NMR-based pore size distributions with core-based pore body and throat size distributions.
The approach was applied to the water-flood projects for Mina el Carmen formation reservoirs, San Jorge Basin, Argentina, in a pilot project involving multiple wells. The initial estimate of lifetime cumulative oil production was estimated with conventional-analysis prediction. Based on MRIL and core data analysis of a pilot well, the water-flood filtration program was changed, and successful water injection has continued for over two years. The cumulative oil production exceeds the initial estimate by more than a factor of 2. The particle-size correlation derived from the key well was found applicable to other wells in the same formation and water injection was applied to four oil-bearing zones. NMR logs were acquired for five of the seven wells in the project. The pore-size distributions derived from these logs are used to adjust the threshold particle size in the filtration program of the individual wells. To date, all of these wells have been producing successfully.
Reservoir Optimization in Full-Field Development Using Geosteering Techniques to Avoid Existing Production Completions
Authors: Edwards John , Hillock Peter , Pogson Mark , Nichol Gordon 
Published: December 2007

Abstract
To maximise drainage, the full field development phase of the Wandoo oil field required three new horizontal wells to make a total of five crossings with two existing horizontal wells. The low relief structure and potential coning from nearby fluid contacts required three of these crossings to be within a vertical separation of 2 m. Because this clearance is much smaller than the closest safe approach possible using geometric collision avoidance, geosteering was used as the collision avoidance technique. This required a detailed resistivity and gamma ray model of the stratigraphic sequence, which was used to establish the relative position of the existing and new wellbores. The well-crossings were made by geosteering in the formation layer either over or under that of the existing well. Three crossings requiring the closest approach had separations computed to be 2.6, 2.4 and 1.7 m. These separations are much closer than the minimum allowable 5.2 to 7.1 m for geometric collision avoidance, but are far enough apart to avoid fracturing between the wells.
As the horizontal drainholes dropped down the updipping sequence they were geosteered within two reservoir units. One unit has a 0.6-m sweet spot, and each unit has its own upper and lower coning boundaries. This reservoir geosteering also required a resistivity and gamma ray model, in order to build a real-time geological cross-section. This cross-section was used to intersect and follow the sweet spot, and design sidetracks if faults or rapid dip changes caused the well to enter a reservoir unit outside its coning boundary.
The well crossings allowed approximately 7 million barrels of reserves to be successfully exploited without putting the existing wells at risk. Production from the field was above budget estimates, which was due primarily to the high efficiency in placing the well bore in good quality rock and the contribution from the crossed wells.
A Case History Study - Evaluation of San Andres Stimulation Results
Authors: Black Harold N. , Stubbs Bruce A. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

Abstract
Frequently, it is asked: "What is the best stimulation method for the San Andres formation? Under what conditions is it better to fracture, acidize or to fracture-acidize?" An objective of this study is to help in the designing of future treatments and evaluating previous treatments in similar type reservoirs.
This case history study is an evaluation of hydraulic fracturing, acidizing and fracture-acidizing treatments in approximately 25 wells in 5 fields producing from the San Andres formation in producing from the San Andres formation in the Permian Basin (Fig. 1). Most of these fields are now being waterflooded. Actual and theoretical productivity index ratios calculated by three methods were compared by plotting these ratios versus both actual and dimensionless times. Oil, water and total production rates were cross-plotted versus time production rates were cross-plotted versus time to help explain deviations of actual from the theoretical productivity index ratio curves.

Introduction
A lithogical study has indicate that three basic San Andres rock types, lagoon, backreef and reef, resulted from variations in the depositional environment during the Permian Period of the Paleozoic Era. When the seas covered the Paleozoic Era. When the seas covered the present Permian Basin area, the larger present Permian Basin area, the larger particles of corals and fossil fragments particles of corals and fossil fragments settled and formed reef-banks in the high energy zone away from the shoreline. These reef-banks later formed high porosity, high permeability formations porosity, high permeability formations classified as reef type rock. Shelfward from these banks, the quiet water envirollment allowed finer particles to deposit which later resulted in the lower porosity backreef type rock. In the porosity backreef type rock. In the shallow water near the shoreline, even finer grained sedimentation eventually caused the formation of lagoon type rock. The lagoon type rock, at the present time, due to its low porosity, is generally not considered commercially productive of hydrocarbons unless it contains productive of hydrocarbons unless it contains natural fractures.
Development of a Single-Trip Method for Shallow-Set Casing Shoe Testing and Openhole Drilling
Authors: Coronado Martin P. , Frisby Ray A. 
Published: December 2007

Abstract
This paper describes the development of a new method for drilling out a shallow-set casing shoe, testing pressure integrity at the shoe, and drilling open hole below in a single drill pipe trip in a deepwater drilling environment. This methodology should reduce the cost of drilling operations, particularly in locations with shallow-water-flow potential.
The development and operation of a new drillstring-integral shoe test packer system will be described that allows isolation of the bottom of a shallow-set casing string for purposes of pressure testing the shoe. This provides the operator with a method to verify shoe integrity prior to drilling into high-pressure sands, which have potential for water flow1, with fewer drill pipe trips.
The paper will also present a detailed case history of how this method was applied for a major offshore operator from a floating vessel in 4,000 ft of water in the Gulf of Mexico. For this application, shoe-testing of the 30-in. casing string was critical to check for resistance to potential shallow-water-flow reaching the surface. This test operation was also performed riserless, without a means to perform the shoe pressure test other than the drill pipe string. If the shoe test proved successful, the operator could continue drilling the next wellbore section without pulling the workstring, thus streamlining the operation and saving time.
Performance criteria required by the operator, the design methodology used to meet those criteria, qualification testing and field performance in initial operations, including time savings from the one-trip system will also be discussed.
Evaluating Hydraulic Fracturing in Cased Holes Using Cross-dipole Acoustic Technology
Authors: Tang X. M. , Patterson D. , Hinds M. , Cheng N. Y. 
Published: December 2007

Abstract
A cross-dipole technology was used to evaluate a carbonate formation in Southeastern New Mexico to determine fracture trends in a water-flooded environment. The measurements were first made in openhole, then in casedhole before and after fracture stimulation. The cross-dipole data were processed to find the amount of anisotropy and the associated azimuth. The results demonstrate that stimulated fractures create a substantial anisotropy and well-defined azimuth behind casing. More important, by evaluating the anisotropy value and the azimuth from the casedhole data, we can determine the fracture extent along the borehole and its azimuth in the formation. The fracture extent is also consistent with that from a radioactive tracer measurement. The results of this study suggest that cross-dipole acoustic logging is an effective technology for casedhole fracture stimulation evaluation.