bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Ultrashort Radius Radial System Applied to Thermal Recovery of Heavy Oil
Authors: Dickinson Wade , Dykstra Herman , Nees J. M. , Dickinson Eric 
Published: December 2007

ABSTRACT
Over 1,000 horizontal and curved radiais have been placed in unconsolidated, sandstone and limestone formations in the U.S. and Canada with the Ultrashort Radius Radial System. All radiais are drilled with high pressure, water-based fluids (69 MPa (10,000 psi)) with appropriate additives. These radiais move from the vertical to the horizontal around a 30 cm (1 ft) radius of curvature. Multiple radiais (up to 20 per layer) and multiple layers (up to 5 layers) have been successfully drilled. Most radiais have been positionally surveyed. Horizontal completions including open hole, Flexible Sand Barrier (flexible permeable casing), and gravel packing have been employed. Some radiais have been placed using Control While Drilling which incorporates real-time downhole indication of drillhead trajectory coupled with real-time trajectory control supplied by small thrust jets which move the drillhead up or down so as to follow a desired trajectory.
Field conditions of water coning, natural fracturing, hard-soft inclusions, shale partitions, faulting, and other common reservoir heterogeneities have been encountered. Applications have been made in both heavy and light oils. A typical successful controlled injection/production (huff and puff) application of the system with production results is described in detail.
An Emerging Economic View of World Natural Gas Demand and Supply
Authors: Dorsett W. H. , Ackerman G. B. 
Published: December 2007

ABSTRACT
Natural gas is swiftly moving from a locally traded commodity in regional markets to a globally traded commodity. This paper describes a numerical model of international gas trade which evaluates the effects of inter- and intra-regional gas trade on demand, supply and price.
Preliminary evidence indicates natural gas prices are 15 to 30% lower in real terms when inter-regional trade occurs and local consumption of natural gas increases relative to fuel oil in the local market.
Natural gas developers or marketers that explicitly consider the inter-regional impacts of gas trade will have a greater likelihood of understanding the risks in marginal projects and are more likely to embrace economic projects and eschew non-economic projects.
The Future Gas Market in Europe: Opportunity or Dilemma to the Producer
Authors: Lindberg Per 
Published: December 2007

Abstract
The views of a major North Sea gas producer on the future development of the European markets for natural gas will be presented by Statoil.
The presentation will focus on the anticipated growth of the demand for gas in Europe and discuss the main driving forces, such as environmental concerns, gas demand for power generation, diversity of energy supply and the emerging opportunities in Eastern/Central Europe. Further more the views from a supplier and a gas seller observing the possible, future structural changes of the European gas market now subject to discussion and definition in the European Community will be presented. In conclusion, the consequences for Norway as a gas supplier will be discussed.
New Developments in Petroleum Investment Contracts
Authors: Walde Thomas 
Published: December 2007

Abstract
Since there have been structures of public government, economic interest in minerals and technical ability to extract them, there has been mineral legislation and methods of giving permission to miners - by the owners of the land or the owner of subsurface mineral rights - to extract them. Issues which we now consider important, for example, access to land, payment to the owner/sovereign for extraction of minerals, supervision of mining activities and safety, both for miners and third parties, ancillary economic contribution of mining to local communities - have been around for a very long time. These issues are still relevant and their regulation - in legislation, subsidiary regulations, in mineral agreements and licensing conditions -evolves and responds to advances in technology, to new economic concepts and financing methods, to new political attitudes and constraints.
When viewing current licensing methods negotiatiated petroleum and mineral development agreements - one can therefore both come to the conclusion that nothing is veritably new and that current agreements contain significant innovation.
The present paper does therefore not pretend to claim that there is a revolution with dramatic innovation in current licensing, but rather surveys the -sometimes substantive, sometimes rather more formal - changes in current licensing and negotiating practice.
Current licensing & negotiating has to be viewed before the political and economic background:
The 1970s were the time of strong assertion of state sovereignty, over economic and political emancipation of developing countries resulting in large-scale nationalization, renegotiation, emergence of strong state resource companies supported by foreign loans. Resource endowment was seen as an important lever to gain economic power and private investment was excluded, restricted and constrained, an attitude best illustrated in Decision 24 of the Andean Pact of 1976. This attitude has changed, first gradually and currently, in the aftermath of the collapse of the supposedly ever-rising petroleum price in 1985 and the wake of the collapse of state socialism, with dramatic speed, scope and depth. Encouragement of foreign investment is the order of the day, remnants of the 1970s restrictions are dismantled everywhere, ex-socialist countries are rushing into foreign investment as a panacea for their woes and strongly entrenched state enterprises are being restructured and move towards privatization.
Trends in Production-Sharing Contracts in Nigeria
Authors: Ofoh E. P. 
Published: December 2007

ABSTRACT
Nigeria, as a member of the Oil Producing and Exporting Countries (OPEC), today operates various forms of Joint Venture arrangements. From 1908, when oil exploration first began in Nigeria by a German company, the Nigerian Bitumen Corporation (NBC), through 1937 when Shell D'Arcy took concession of the entire country as a single block to 1972 when more than 13 international companies joined the entrepreneurship, the Nigeria Petroleum Industry has witnessed numerous forms of Production Sharing Contract agreements. These arrangements which reflected state of the art of industry at the time, ranged from simply Tax and Royalty only through "Equity Sharing" to "PRODUCTION SHARING" AGREEMENTS. In addition, each phase of these agreements partly reflected the following:
Prevailing Fiscal and Economic Environment in the Country. National Development and International Obligations/Needs. State of Global Economy.
This Paper will discuss among other things:
– The Economic implications of each arrangement to both Joint Venture partners. – The possible future trends and their implications. – The salient points in each arrangement shall be highlighted.
Non-Commercial Risk and Financing Energy Investments in the Least Developed Countries - The Case of Africa -
Authors: BONO J. 
Published: December 2007

Abstract
Since there have been structures of public government, economic interest in minerals and technical ability to extract them, there has been mineral legislation and methods of giving permission to miners - by the owners of the land or the owner of subsurface mineral rights - to extract them. Issues which we now consider important, for example, access to land, payment to the owner/sovereign for extraction of minerals, supervision of mining activities and safety, both for miners and third parties, ancillary economic contribution of mining to local communities - have been around for a very long time. These issues are still relevant and their regulation - in legislation, subsidiary regulations, in mineral agreements and licensing conditions -evolves and responds to advances in technology, to new economic concepts and financing methods, to new political attitudes and constraints.
When viewing current licensing methods negotiatiated petroleum and mineral development agreements - one can therefore both come to the conclusion that nothing is veritably new and that current agreements contain significant innovation.
The present paper does therefore not pretend to claim that there is a revolution with dramatic innovation in current licensing, but rather surveys the -sometimes substantive, sometimes rather more formal - changes in current licensing and negotiating practice.
Real-Time Expert Systems for Drilling Operations Support
Authors: Corti Martino , Galinetto Rita , Sansone Aldo 
Published: December 2007

AbstractThis paper describes ADIS Real Time Expert Systems (RTES) status and results. An overview is given both on ADIS Project and its Real Time System of which RTES are partDrilling know-how is used to drive RTES in trasforming raw and bulky sensors data to high level and compact drilling information. This includes operating state determination, time analysis, data validation, trends evaluation and alarm generation. Currently under development are expert systems to support the handling of critical events, namely kicks and pipe stickings.At the moment RTES are operated as a part of the whole ADIS Real Time System at one rig site and in AGIP main offices. At least one further rig site and one district office will be operating by the second half of 1992.
Properties and Application of Delayed-Release Breakers
Authors: Parker M. A. , Laramay S. B. 
Published: December 2007

ABSTRACT
Water-base fracturing fluids gelled with guar-based polymers are used for fluid loss control, viscosity development, and proppant placement in hydraulic fracturing operations. These polymers must be subsequently degraded with breakers such as enzymes, oxidizing agents, or acid. Prevention of premature reaction of these additives with the fracturing fluid may be accomplished by encapsulation of these breakers, thereby providing a delayed release. Many aspects concerning selection, testing, design, and application of delayed release breakers have been investigated and are presented in this paper.
Laboratory testing has been done, including (1) methods of product preparation and corresponding release profiles, (2) viscosity degradation using delayed release breakers and conventional breakers, and (3) determination of breaker requirements. Fracture conductivity data are also presented to show the benefit of these materials to improve the results of a treatment. Case histories are presented to show results of the application of these materials.
Integral Type Curves for Advanced Decline Curve Analysis
Authors: Spivey J. P. , Gatens J. M. , Semmelbeck M. E. , Lee W. J. 
Published: December 2007

ABSTRACT
This paper introduces a new family of type curves for advanced decline curve analysis. The new type curves are obtained by combining the dimensionless production rate and the dimensionless cumulative production on a single log-log scale. The new type curve offers two significant advantages: 1) observed cumulative production data is much smoother than observed production rate data, making a match easier to obtain with the new type curve; and 2) simultaneously matching both rate and cumulative production provides more confidence in the selection of the correct early- and late-time stems. Plotting functions are presented to allow the new curves to be used for both oil and gas wells produced at either constant or varying flowing bottomhole pressure. Use of the new type curves is demonstrated for both simulated and field data.
New Developments in Nitrogen in the Oil Industry
Authors: Evison Brian , Gilchrist R. E. 
Published: December 2007

Abstract
The generation of nitrogen for Enhanced Oil Recovery has reached a degree of sophistication such that almost any size project can be considered. In the past, one limiting factor has been the availability of small (economic) nitrogen producing plants. The recent development of small nitrogen producing plants utilizing membranes has allowed the use of nitrogen to be considered for many new opportunities.
Membrane produced nitrogen can be used in areas where natural gas is not available. For example, it finds instant application in attic oil reservoirs both on-shore and off-shore, where a "huff-and-puff' procedure is applicable. Nitrogen from membrane systems can be used in coal-bed methane projects. Membrane systems, like cryogenic air separation plants, are now available where a "third-party" owns and operates the system on a supply contract.
Nitrogen gas for the oil industry is now more readily available in a greater size range, and for any time period.
Analysis of Inflow Performance Simulation of Solution-Gas Drive for Horizontal/Slant/Vertical Wells
Authors: Chang Ming-Ming 
Published: December 2007

ABSTRACT
The inflow performance relationship (IPR) developed through numerical simulation of vertical, horizontal, and slant wells in solution-gas drive reservoirs was analyzed. The IPR is essential to optimize production design; however, little information is available for interpreting the change of IPR with wellbore geometry and depletion stages. Gas saturation, PVT properties, and formation pressure close to a wellbore were investigated to interpret the shape of IPR curves at various flowing bottomhole pressures and stages of depletion. The effect of oil gravities on IPR curves was studied, and newly developed IPR curves for slant wells were compared to those for horizontal and vertical wells.
Horizontal well IPR curves fall on both sides of Vogel’s reference IPR curve for a vertical well. Horizontal wells show a better productivity improvement with additional pressure drawdown than vertical wells at the early stage of depletion. Horizontal well IPR curves increase their curvature with depletion up to 8% then slightly decrease in curvature at later stages of oil recovery. This trend, different than that found for vertical wells, is due to a high gas production rate from horizontal wells at low bottomhole pressures before oil recovery reaches 8%. The decrease in curvature of IPR curves for a vertical well with depletion is due to a slightly higher formation pressure around the wellbore at lower flowing bottomhole pressures at later stages of depletion.
Spirit (Minnelusa "A") Unit: A Case Study in Unitization
Authors: King W. A. , Flahive R. M. , Zwart D. W. 
Published: December 2007

ABSTRACT
Many Minnelusa fields in the Powder River Basin have been successfully unitized and water-flooded. However, forming the Spirit (Minnelusa "A") Unit was more complicated than most. This Unit required the lawyers, geophysicists, landmen, and engineers to each solve a piece of the puzzle, which when fit together formed the Unit.
The main producing well in the Spirit field lies outside the boundary of the Lily (Minnelusa "A") Unit. Reservoir production and pressure response indicated it was draining a fairly large area and was not responding to nearby water-floods or supplied by a natural waterdrive. Drilling to the north, east and south failed to find commercial pay. Apparently, the Spirit (Minnelusa "A") field extended west into the Lily (Minnelusa "A") Unit. However, it was producing from a Minnelusa "A" accumulation which was not in hydraulic communication with the Lily reservoir.
This paper describes how the ownership problem was resolved, the field was defined, the injection and production responses forecasted and how the water-flood actually has responded to date.
Estimation of Effective Permeabilities for Reservoirs Initially Above Bubblepoint Pressure
Authors: Hatzignatiou D. G. 
Published: December 2007

ABSTRACT
This work investigates the effects of initial reservoir pressure on the computation of effective permeabilities for homogeneous and heterogeneous solution-gas-drive reservoirs which are initially above the bubble-point pressure. The heterogeneous system considered is that of a two-zone composite reservoir with different absolute permeability and/or relative permeability curves in the two regions. It is shown that the initial effective oil permeability may be estimated from drawdown and buildup pressure data. It is also shown that one can obtain accurate estimates of computed effective permeabilities as pointwise functions of wellbore pressure from drawdown data during the time period that the wellbore pressure is less than the initial bubble-point pressure. From the estimates of effective permeabilities obtained, it is shown that for the case of homogeneous solution-gas-drive systems one can construct approximate effective (or relative) permeability curves by nonlinear regression analysis techniques. For the case of heterogeneous solution-gas-drive reservoirs it is shown that if the initial reservoir pressure is above the reservoir bubble-point pressure then the effective oil permeability of the inner or the outer zone might be obtained from the analysis of drawdown and/or buildup pressure data.
Pressure Transient Analysis for a Three-Region Composite Reservoir
Authors: Ambastha A. K. , Ramey H. J. 
Published: December 2007

ABSTRACT
Usually, well tests from enhanced oil recovery projects, such as steam injection, in-situ combustion, and CO2 flooding projects, are analyzed using a radial, two-region composite reservoir model. However, a three-region model may be more appropriate in many cases. An analytical solution for the transient pressure response of a well in a radial, three-region reservoir is available. But a detailed study of the transient pressure and/or pressure derivative response of a well in a three-region reservoir has not been presented in the literature.
Using an analytical solution, this study establishes the ratio of the intermediate region radius to the inner region radius as a correlating parameter for the transient pressure derivative responses for a three-region reservoir. Additional four parameters are related to the mobilities and the storativities of different regions. This study shows that the deviation time method would result in an estimate for the inner region radius, if the effects of the mobilities and the storativities of the inner and the intermediate regions are not balanced in a way to produce an incorrect deviation time.
Analytical expressions for the effective porosity-compressibility product and mobility are developed for the analysis of pressure transient data by the pseudosteady state (PSS) method. The PSS method would result in an estimate of the combined volume of the inner and the intermediate regions, if an effective porosity-compressibility value is used to analyze the pseudosteady data. However, at times, the development of an apparent pseudosteady state may yield an overestimated volume. An idea about the development of an apparent pseudosteady state may be obtained by calculating the effective dimensionless time corresponding to the time to start of an approximately constant Cartesian slope for the pressure transient data in question.
Formation Heating and Oil Recovery by Steam Injection into Linear Porous Media
Authors: Avendano Horacio , Magnani Charles F. , Farouq S.M. 
Published: December 2007

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
Mathematical models were developed for predicting the extent of the heated zone in predicting the extent of the heated zone in steam injection into a linear porous medium, having a circular or rectangular cross-section, surrounded by an infinite, heat-conducting medium. The models were used to predict the steam zone advance in typical oil reservoirs. Results were compared with those obtained when using models for uniform thickness formations. The heat loss behavior for the two types of models was also compared.
The mathematical models were further employed to predict the growth of the heated zone in a typical laboratory system, in particular a core which consisted of an uninsulated particular a core which consisted of an uninsulated steel pipe, filled with glass beads, the surrounding air serving as the infinite heat-conducting medium. Good agreement was obtained between the predicted and the experimental results.
The mathematical models were extended for prediction of oil recovery from laboratory cores, prediction of oil recovery from laboratory cores, using continuous steam injection. Examples of such predictions are given and compared with experimental data.
The proposed mathematical models provide an important means of correlating laboratory data, and make it possible to obtain useful information from experiments. Moreover, in a number of field situations the models may provide better predictions of formation heating provide better predictions of formation heating than the existing models.

Introduction
Injection of a hot fluid into a porous medium results in the formation of a heated zone, which, at any given time, is related in a complex manner to the instantaneous rate of heat injection, heat losses up to the time of interest, and the heat utilized for heating the porous medium and the fluids contained in it. porous medium and the fluids contained in it. Marx and Langenheim presented a theoretical treatment of this type for steam injection into a formation of infinite areal extent, and uniform thickness, with infinitely thick formations overlying and underlying it. Ramey extended this treatment for a variable injection rate.
The present work considers the injection of steam into linear porous media, having circular or rectangular cross-sections, situated in infinite heat-conducting media. The calculated steam and hot water front positions can be employed for computing oil recovery using the method proposed by Willman et al.