bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Southern Cone Petroleum Market
Authors: Fidalgo Santiago , Astra C. A. P. S. A. , Pisani Walter 
Published: December 2007

ABSTRACT
The Argentine oil sector has been moving strongly toward complete deregulation since 1989. Price controls on byproducts has been lifted, old petrolem contracts became into concessions, and the state oil company, YPF, is under process of privatization.
In this context, the international companies scouting for opportunities can find an important menu of potential investments.
But there remain some problems connected with this deregulation, too. The lack of a reference crude and product market price is one of them.
This paper focuses how to overcome this trouble with the establishment of an
References and illustrations at the end of the paper. institutional market for crude and products, not only for Argentina but also for the entire Southern Cone Region (Argentina, Bolivia, Brazil, Chile, Paraguay and Uruguay), inquiring into the benefits of its creation.
Those countries should follow Argentine steps in deregulation (more probably sooner than later). All of them, except Bolivia and Chile, have signed in 1990 the "Mercosur" treaty, which favores this type of enterprises.
Furthermore, it will be analyzed the incidence of this market in the oil trade, intraregional, or between the Southern Cone and the rest of the world.
Prop-Packed Fractures - A Reality On Which Productivity Increase Can Be Predicted
Authors: Wendorff C.L. , Alderman E.N. 
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
Production increases resulting from fracture treatments should be based on the conductivity and location of the propping agent - not on the area created by the frac fluid. Model studies show that in conventional fracture treatments propping agents settle to the bottom of a fracture forming a packed pile of prop. The location and dimensions of the pack are dependent on the physical properties of the prop, fluid and physical properties of the prop, fluid and formation, the geometry, volume and length of the fracture, and the pump rate.
This paper presents a mathematical procedure for predicting the location and procedure for predicting the location and dimensions of the prop pack in a vertical linear fracture. A computer program has been prepared and is currently being used in designing fracture treatments.

Introduction
Studies we have made in models of vertical and horizontal fractures show that in conventional frac treatments props end up in a multilayer packs. We observed this in models where no leak-off occurred as well as in a vertical model with leak-off through one face. Other authors have demonstrated the same phenomena. To the best of our knowledge no one has published model studies which demonstrate that monolayer or partial monolayers are obtained in conventional frac treatments, i.e., where low viscosity gelled oil or water is used as the fracturing fluid.
With few exceptions field treatments designed on the basis of monolayer or partial monolayer concepts have not responded any better than conventionally designed treatments. Lab studies, on the other hand, show fracture conductivities of partial monolayers are much greater than conductivities of a pack. We believe this inconsistency is evidence a pack occurred.
Our model studies supplied a considerable amount of equilibrium velocity data. Earlier work had described the areal extent of a prop pack where no leak-off occurred. Our goal was pack where no leak-off occurred. Our goal was to describe both the areal extent and location of the prop pack under conditions where leak-off occurred.
A New Approach to Preventing Lost Circulation While Drilling
Authors: Fuh Giin-Fa , Morita Nobuo , Boyd P. A. , McGoffin S. J. 
Published: December 2007

ABSTRACT
This paper presents a new concept, theoretical formulations, and field test results of the loss prevention material (LPM*) developed for use in many possible applications such as high-angle and horizontal well drilling, drilling through severely depleted formations (to optimize casing requirements), drilling through highly tectonically active areas (i.e., regions of over-thrust faults and salt dome structures) where the in situ rock stresses are high and directionally unequal. Both open-hole microfractures and 5000-ft open-hole leak off tests using LPM were successfully conducted in our wells in Newkirk, Oklahoma, and Ventura, California. LPM is a specially selected (material strength and specific gravity) and narrowly sized granular material which, after being fully mixed in oil or water based mud at an optimum concentration, can provide good protection to formations against lost circulation while drilling.
Higher formation fracture resistance resulting from the use of LPM in drilling fluids can reduce or prevent the occurrence of lost circulation while drilling. This paper will show that a remarkable increase of 8.0 ppg in borehole breakdown pressure was achieved in one of our tests in the Newkirk well. An increase of fracture propagation pressure in the range of 3.0 to 6.0 ppg was recorded in the field tests. These results are in general agreement with our laboratory findings also discussed in this paper.
New Standard Set for South Texas Drilling Performance
Authors: Simon J. M. 
Published: December 2007

ABSTRACT
This paper describes the drilling performance, techniques and equipment used to attain a 50 percent reduction in rig days during Shell Western E&P Inc.’s (SWEPI) 13 well redevelopment drilling program. One of the wells drilled during this program reached a depth of 14,450 ft in less than 17 days (This is believed to be the fastest onshore geopressured well ever drilled to this depth). Additionally, two world record bit runs for cumulative footage with an 8.5-in. bit were attained.
In 1989 a redevelopment drilling program began on the A. A. McAllen "B" lease located in Hidalgo Co., TX. These wells were land locations drilled to an average depth of 14,500 ft with typical bottom pressures of 13,550 lb/in2 (psi) and bottom hole temperatures of 350°F. These wells were drilled as infield wells and several wells experienced pressure depletion related problems during the drilling process. Numerous improvements in all aspects of the drilling operation were made during the drilling of these wells. The 14 previous wells drilled on this lease averaged 66 days from spud to rig release. The 13 redevelopment wells averaged only 33 days (50 percent average improvement).
This paper will review the drilling history on the lease and then discuss the various factors and techniques which have led to this dramatic improvement in drilling performance. Also included in this paper are the results seen while using different mud systems to drill these wells.
Case Histories of MWD as Wireline Replacement: An Evolution of Formation Evaluation Philosophy
Authors: Cantrell L. A. , Paxson K. B. , Keyser B. L. , Ball Scott 
Published: December 2007

ABSTRACT
Since its introduction in the late 1970's, measurement while drilling (MWD) technology has evolved from an auxiliary directional drilling service to a fully integrated logging package for quantitative reservoir characterization. Many major and independent oil companies are now re-evaluating traditional formation evaluation methods, commonly utilizing MWD technology as a replacement for routine wireline logging services.
Recent MWD logging case histories are presented from the Texaco operated Kilauea (Green Canyon Blocks 6 and 50) and Tick (Garden Banks Block 189) Projects from the Gulf of Mexico Flexure Trend for the purpose of evaluating their utility for quantitative reservoir characterization. Single and multiple depth of investigation resistivity, formation density, neutron porosity, and dual gamma ray MWD responses are compared and contrasted with their correlative wireline counterparts. Petrophysical evaluations are corroborated by conventional core data, borehole images, sidewall core, and production data. MWD "near/far" neutron count rate overlays were employed for qualitative evaluation of hydrocarbon type. Measurements after drilling (MAD) were recorded for indication of relative permeability and detection of moveable hydrocarbons.
Comparative evaluations proved conclusively that MWD could be used as a substitute for correlative wireline logging suites where borehole size was not a limiting factor. Texaco's recent experience with MWD has evolved from that of a "last resort" application toward that of a primary logging suite for formation evaluation. This philosophical change in utilizing MWD has resulted in significant savings in rig time and associated costs. Additionally, difficult, well plans were drilled and evaluated with confidence; geopressure was safely monitored; and tops of conventionally cored intervals were selected. Geological interpretations and quality operational decisions were made before the wells reached total depth, creating a more efficient business process.
Cenezoic Uplift and Caprock Seal in the Barents Sea: Fracture Modelling and Seal Risk Evaluation
Authors: Makurat Arel , Torudbakken Bjørn , Monsen Karstein , Rawlings Colin 
Published: December 2007

Abstract
Among the possible reasons for leakage from reservoirs in the Barents Sea are spill due to tilting, expulsion caused by gas expansion and cap rock failure. All mechanisms have been related to the pronounced Cenozoic uplift of the Barents Shelf.
This paper focusses on how the uplift has influenced the cap rock seal. The simulations presented comprised Late Jurassic rifting at shallow burial, post-rifting sedimentation followed by two phases of Tertiary uplift/erosion with subsequent compression and extension at different depths of burial. The two main results from these simulations are: a) that cap rock failure may occur due to the build up of deviatoric stresses during uplift, and b) that minimal strain is required to initiate fracturing during extensional or compressional tectonics.
By combining the map of total erosion with the results of the fracture modelling study presented, uplift could be identified as a critical factor in structurally high areas. Fracture initiation in cap rocks is less likely in basinal areas. As a result exploration can be concentrated on the most promising areas.
Reservoir Characterization With Probability Field Simulation
Authors: Srivastava R. M. 
Published: December 2007

Abstract
Probability field simulation is a general methodology for producing equiprobable models of rock and fluid properties that honor the available data, and that honor the distribution and spatial continuity of the property being modelled. This paper introduces the basic idea behind probability field simulation, documents the practical application of the method through case studies, and discusses its strengths and weaknesses.
Proppant Convection and Encapsulation in Hydraulic Fracturing; Practical Implications of Computer and Laboratory Simulations
Authors: Cleary M. P. , Fonseca Amaury 
Published: December 2007

Summary
Our work shows that the most important single consideration in hydraulic fracturing should be downward convection of heavier proppant-laden stages in vertically uncontained fractures. This mechanism has been absent in simulators and design approaches used by the industry: some industry personnel still refuse to accept the negative implications of extensive vertical fracture growth and, even when accepted, the convection process cannot be handled by current industry models. The efforts reported here are aimed at quantifying the phenomenology involved and incorporating the results into a practical simulator, developed for the Gas Research Institute (GEI), which also uniquely represents the physics of 3-D rock deformation and fluid flow. Two major conclusions should greatly affect field practice: Convective downward motion, even in simple fluid treatments, dominates over particle settling.Encapsulation of viscous fluids by low-viscosity fluids available (e.g. gas/water) greatly accelerates the process.
Our quantification covers a range of fluids and fracture opening behavior, for both laboratory conditions (as verification) and for typical field job schedules. Super-computer simulations were required for detailed analysis of the processes involved, but the experience gained is being down-loaded to a simpler practical fracture analysis system, which was adapted to run on portable (PC) machines, for on-site implementation and re-design of treatments, based on real-time analysis of data collected. Such simulations show that convection should be the dominant mechanism in fracturing of most reservoirs and this leads to a series of practical recommendations which are greatly at odds with "conventional wisdom" in the industry, with resulting major implications for the execution, cost-savings and benefits of fracturing.
Modeling of Gas Rates Through 1-in., Nitrogen-Charged Gas-Lift Valves
Authors: Acuña H. G. , Schmidt Z. X. , Doty D. R. 
Published: December 2007

Abstract
The main objectives of this study were to test three one-inch nitrogen-charged gas-lift valves from different manufacturers and to develop or modify existing procedures to accurately predict valve flow performance. During the testing program more than 360 air flow performance curves were collected under simulated downhole conditions. Injection pressures ranged from 400 psig to 1800 psig and sampled data included orifice, throttling and transition flow regimes. Various techniques to calculate the minimum injection pressure to sustain orifice flow based on the dynamic tubing sensitivity, were also investigated.
Testing demonstrated that different valves experience different flow rates, even when the port sizes installed in the gas-lift valves are the same. Our study showed that one-inch valves have lower flow capacities than 1-1/2-inch valves. Various sensitivity tests were performed to identify which valve components obstruct the flow in the smaller valves. Testing procedures to fully describe the flow characteristics of gas-lift valves are also presented. These procedures were proposed to be adopted as API Recommended Practice 11V2 for gas-lift valve testing methods.
Fracturing Unconsolidated Sand Formations Offshore Gulf of Mexico
Authors: Monus F. L. , Broussard F. W. , Ayoub J. A. , Norman W. D. 
Published: December 2007

Abstract
This paper presents case histories for two offshore Gulf Coast wells completed with hydraulic fracture stimulation treatments followed by gravel pack installation. This completion technology is relatively new to the Gulf Coast area and is being employed to address the unique sand conditions encountered with unconsolidated sandstone reservoirs.
Successfully fracturing soft sandstone formations poses different challenges than fracturing hard-rock reservoirs. The tip screenout design technique is used for fracture design to ensure that the fracture width and proppant concentrations are adequate to efficiently connect the reservoir to the wellbore. Downhole pressure measurements and multiple-tracer isotope tagging of fracturing fluids and slurry are used both for on-site design aids and post-job evaluation. The case histories presented demonstrate that hydraulic fracturing of soft sandstones can provide effective stimulation when properly executed.
Field and Laboratory Experience in Closed Fracture Acidizing the Lisburne Field, Prudhoe Bay, Alaska
Authors: Bartko K. M. , Conway M. W. , Krawietz T. E. , Marquez R. B. , Oba R. G. M. 
Published: December 2007

ABSTRACT
This paper describes the laboratory and field work performed to understand and improve the stimulation of the fractured carbonate formation producing in the Lisburne Field, Prudhoe Bay, Alaska. Within the producing formations, the lower Wahoo intervals are low permeability, fractured dolomitic zones that produce poorly when compared to the higher permeability upper intervals. Past attempts to stimulate these intervals have included propped fracture techniques and standard acid fracture techniques. A laboratory study evaluated the effects that various acid systems have on Wahoo rock properties, the degree of permeability enhancement, and stability of acid fracture conductivity. Various acid fracturing techniques were also investigated to determine which technique and acid system created long-term fracture conductivity. The laboratory study indicated the optimal treatment would be obtained by using emulsified acid in a fracture acidizing treatment followed by a closed fracture acidizing stage using emulsified acid. The unique combination of this particular acidizing technique and acid system has increased productivity in the Lisburne Field.
Complete documentation of the field work optimization program is included in this paper. Pressure buildup (PBU) analysis has indicated fracture half lengths are from 25–100 feet long and production spinner surveys have determined that lower intervals are contributing to production. To date, over 40 new and old wells have been stimulated using emulsified acid with the closed fracture acidizing technique. Significant increases in production and reserves are currently being seen from this program.
Geologic and Reservoir Mechanisms Controlling Gas Recovery From the Antrim Shale
Authors: Kuuskraa V. A. , Wicks D. E. , Thurber J. L. 
Published: December 2007

ABSTRACT
The Antrim Shale is one of the most active natural gas plays in the U.S., accounting for more than 10% of all gas well completions in 1991. Yet, geologic and production mechanisms of this large, unconventional resource remain poorly understood. Complex reservoir phenomena controlling production include two-phase flow, gas desorption, and fracture permeability. Current operational practice, which relies on gas-assist to lift formation water and reduce bottom-hole pressure, may not optimize well productivity, currently averaging about 85 Mcfd in the basin.
The reservoir processes controlling gas production in the Antrim Shale involve a combination of characteristics typical of three types of unconventional reservoirs: coalbed methane, fractured shales, and tight gas sands. Adsorption, as the primary gas storage mechanism, requires lower downhole operating pressures to achieve gas production. Fracturing of the Antrim, as the primary process controlling natural permeability, requires improved knowledge of fracture density, dimensions, and geometry. Free gas stored in micropores within the shale matrix, similar to tight gas sands, requires an understanding of water and gas saturation. This makes the Antrim Shale a "triple-porosity" system which requires the development of new reservoir modeling tools to predict well productivity from test and early time production data.
A simulation sensitivity study was conducted on the Antrim Shale using the COMETPC-3D reservoir simulator. This study varied fracture spacing, porosity, sorption time, matrix compressibility and other parameters to identify the most sensitive variables.
Downhole pumps have recently been introduced to more effectively dewater Antrim wells. These pumps can reduce flowing bottom-hole pressure to 50 psi, sufficient to achieve favorable relative permeability and to improve gas desorption. A GRI-funded field project at NOMECO's Bagley East Project which converted a gas-assist Antrim well to downhole mechanical pumping led to a 116% increase in gas production, demonstrating the importance of dewatering and BHP reduction in optimizing Antrim gas production.
Cotton Valley Production Enhancement Team Points Way to Full Gas Production Potential
Authors: Hunter J. L. , Leonard R. S. , Andrus D. G. , Tschirhart L. R. , Daigle J. A. 
Published: December 2007

ABSTRACT
Description of the paper: This paper describes the origin of the Cotton Valley Production Enhancement Team (CVPET), discusses the approach the team has taken to enhance gas production in the east Texas area of the Cotton Valley formation, and presents findings made up to the time of this writing. An exhaustive study of 275 Cotton Valley (CV) wells, operated by 19 companies in east Texas, is in progress; study methods devised on a 17-well pilot test formed the basis for the study methods used on the 275-well sample.
The CVPET was formed after preliminary studies showed that two of every three CV wells were producing below the average rate for the field. Reasons for the vast production swings among wells were (and are) being sought. Companies drilling and producing from the CV formation were invited to join in a cooperative effort to assemble and analyze data that the organizers hoped would lead to gas production at the full potential of each well.
Results, observations, and conclusions: A massive data base on CV completions has been developed. This data base has allowed development of means of normalizing well completion information, thus allowing a fair comparison of completion techniques. An accurate and easy to use technique to compare production potential of CV wells has been developed and tested. Fracture design optimization and maximization of operating company return on investment have been more nearly achieved.
Applications: Techniques described may be used to analyze completion options in any operating area of the world. Specifically, CV well completion designs may be enhanced after analysis using techniques described and discussed. The paper shows the value of cooperative studies and information exchange among operators and service companies.

Technical Contributions
Simulation of a North Sea Chalk Reservoir With Dynamic Rock and Natural Fracture Properties: Case Study of the Valhall Field
Authors: Powley K. D. , Peng C. P. , Ali Nazir 
Published: December 2007

Abstract
Many of the reservoir uncertainties in the Valhall Held are tied to the dynamic behaviour of the reservoir rock. The high porosity chalk is relatively weak and will experience plastic deformation with reservoir depletion. This results in significant rock compaction, matrix and fracture permeability decline, and shrinkage of the field’s dual porosity area with declining reservoir pressure. Rock compressibility ranges up to 120 E-6/psi, current fracture permeabilities are less than 10 percent of initial, and the dual porosity area is currently 20 percent of original areal extent.
This paper outlines the overall approach used to develop a reasonable predictive tool to guide reservoir management decisions. Key elements include a sophisticated mathematical model, prudent data collection, in-depth evaluation of all available information, and a history match approach that requires direct use of actual data. Evaluation and representation of the reservoir’s dynamic rock and natural fracture properties are described in-depth.