bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application Of A Computer Information System To Surveillance And Analysis Of Production Behavior In Complex Fields
Authors: Cronquist Chapman , Hodgson Robert 
Published: December 2007

Abstract
Many oil and gas fields are characterized by extensive faulting and multiple pay zones with lateral facies variation. These fields contain many apparently separate pay-zone segments. Often, however, groups of pay-zone segments. Often, however, groups of these apparently separate segments are in communication and form common reservoirs. Geologic and engineering interpretation in this type of field are subject to continuous revision as new data are received.
Optimal exploitation under these conditions requires early recognition of communication between pay segments, resolution of possible inconsistencies between geologic interpretation and observed production behavior, and determination of reservoir drive mechanism. Continuing analysis is required to indicate areas where new wells should be drilled, zones where existing wells should be recompleted, and reservoirs where fluid injection is needed to increase recovery efficiency. This requires continuous surveillance of large amounts of production and well test information. Resolution production and well test information. Resolution of geologic-production inconsistencies often is a trial and error process which may require interpretive investigation of combinations of pay segments involving many individual well performance histories. Under these conditions, performance histories. Under these conditions, surveillance and analysis using manual techniques is time consuming and expensive. The problem is more one of data management than of geologic interpretation or reservoir analysis.
This kind of problem may be solved economically by using a comprehensive machine data management, retrieval, analysis, and report generating system. This paper describes one such system, called COMPS, which enables the construction and maintenance of large files of production and geologic information and allows selective retrieval, aggregation and reclassification of any desired combination of information about wells or pay segments. COMPS is user-oriented and pay segments. COMPS is user-oriented and does not require prior knowledge of computer programming. All capabilities of the system programming. All capabilities of the system are called upon by the engineer or manager through a set of easily understood commands which utilize terminology, codes, and identifiers suitable to the problem at hand.
The Hot-Film Flow Log--A Formation Evaluation Tool Designed for Shallow In-Situ Oil Shale Experiments
Authors: Thomas Harold E. 
Published: December 2007

Abstract
The Hot-Film Flow Log was developed for evaluating shallow in situ fracturing and retorting (combustion) experiments in Green River oil shale. Two logging probes are described which employ a temperature-compensated conical hot-film anemometer-type flow sensor. Wellbore fluid flow profiles and fluid entry or exit points can be recorded while continuously lowering or raising the probes in cased or uncased wellbores.
Natural, hydraulic, and explosive fractures in oil shale have been evaluated by a combination of air injection, air production, and flow logging techniques. Fracture depths, types (horizontal or vertical), and flow characteristics within a single borehole or a system of boreholes can be interpreted from the logs. Gas flow profiles in in-situ retorting experiments can be determined before ignition, during formation combustion, and after combustion termination.
Limitations and potential applications are discussed.

Introduction
The U.S. Bureau of Mines is presently conducting field experiments near Rock Springs, Wyo., to determine the feasibility of in situ or underground retorting of Green River Formation oil shale at depths of 75 to 450 feet. Most oil shale is an impermeable rock and does not contain oil; however, it contains a solid carbonaceous material known as kerogen which converts to a crude-oil like liquid when heated to 700 degrees to 900 degrees F. To be retorted in situ through a system of wells similar to those in an oil or gas reservoir, oil shale must first be fractured by some means to provide flow paths between wells for injected and produced fluids.
The RamRig Concept For Drilling and Workover Rigs
Authors: Vatne P. A. , Norheim Pal 
Published: December 2007

Abstract
The introduction of the RamRig concept signifies, by its radical new design, a number of substantial savings to both the construction and operation of drilling and workover rigs for the petroleum industry. The RamRig can be used for floating and fixed installations and eliminates the need for large derrick with drawworks, drillstring compensator etc. This novel concept can be used as a small workover to full scale drilling rig and opens perspectives for new ways of drilling wells and for improved economy in future offshore field developments.
Case History: Breitbrunn – Horizontal Foam Drilling Project in an Environmentally Sensitive Area in Bavaria, Germany
Authors: Hanking T. , Rappuhn T. F. 
Published: December 2007

Abstract
A depleted gas reservoir was converted into an underground gas storage in the sensitive Chiemsee lakeshore area east of Munich, Germany. Throughout the project considerable attention had to be given to environmental precautions and noise control. The project involved drilling five horizontal wells to a vertical depth of 1,950 m, with a horizontal displacement through a low-pressure reservoir of about 1,500 m. For the horizontal sections, stable foam was used to ensure safe drilling conditions and prevent formation damage. The foam system was employed for the first time in such horizontal drilling project in Europe. LWD systems for use with foam were not available. In the horizontal sections, paleontological and lithological methods were employed for steering through the narrowe sandstone reservoir. This technology was first tested successfully in a pilot well and then applied to the other four wells. The limited availability of disposal sites and high associated costs made it necessary to minimize the amount of contaminated fluids and cuttings. The liquid phase of the foam was therefore recirculated.
Drill-Cutting Removal in a Horizontal Wellbore for Cementing
Authors: Ravi Krishna , Weber Lawrence 
Published: December 2007

Abstract
For effective zonal isolation, drill cuttings and gelled, dehydrated drilling fluid (GDDF) should be removed from the wellbore before a cement job, but such removal can be a challenge when the wellbore is deviated and the casing is not centered.
This paper discusses simulated wellbore experiments that investigated the effect of different factors on the removal of drill cuttings and GDDF from a horizontal well bore. The parameters studied included eccentricity, flow rate, hole size, casing size, fluids pumped as flush/spacer, and pipe movement.
The results showed that below a certain flow rate, the drill cuttings and GDDF could not be dislodged from the wellbore. In field applications, this flow rate must be known so that job designers can selectively design flushes that will effectively dislodge the drill cuttings and GDDF. As expected, eccentricity also alters the velocity profile in the narrow side of the annulus, and geometry was also a factor in removal efficiency.
The experimental setup, procedure, and results are discussed in detail. Flow rates needed to dislodge the drill cuttings and GDDF are also discussed, A numerical analysis of the fluid flow in wide and narrow annuli was also performed.

Introduction
Cement operators should always use the following guidelines to obtain a successful cementing job.Remove the drill cuttings.Remove the gelled and partially dehydrated drilling fluid. In some cases. this fluid will have the consistency of a paste. Hereafter, it will be referred to as partially dehydrated paste (PDP).Design the cement slurry to meet properties such as pumping time, fluid loss, gas migration, etc. In addition, design the density, rheology, and other placement parameters so that the cement slurry will displace the fluid ahead of it and seal the entire annulus. The cement formulation should also provide zonal isolation over the life of the well.
The removal of drill cuttings and PDP are influenced by the following:–properties of drilling fluid, fluid loss, plastic viscosity etc, a temperature, pressure, differential pressure across the formation–shutdown period–drilling fluid formulation–wellbore details–casing/drillpipe size–hole size–standoff/eccentricity–pore pressure–fracture gradient
For successful PDP removal, the downhole forces in both the narrow and wide sides of the annulus must exceed the yield stress of the PDP under downhole conditions. The force exerted could depend on the following factors:–flow rate of fluid–standoff/eccentricity–properties of fluid–pipe movement–wellbore geometry–scratchers
Although the general effect of these parameters on a cement job is well known, the designer must quantify the effect of each factor to optimize the design of each individual well. For a wellbore with a certain drilling fluid, geometry and standoff, it may be difficult to generate needed forces by hydraulic means only. In such cases, ways to reduce the downhole forces should be explored.
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The Planning and Drilling of a Wildcat Well in the Republic of Seychelles by an Operator-Contractor-Integrated Services Alliance
Authors: Marshall D. W. , Heenan D. H. , Reynolds J. 
Published: December 2007

Abstract
Constant Bank-1 is a 3,200m (10,500ft) wildcat well located in 50m (164ft) of water on a carbonate bank in the Republic of Seychelles, a group of tropical islands in the Indian Ocean.
This paper covers in detail how the contracting philosophy was developed to plan and execute the project through the formation of an alliance comprised of Operator, Drilling Contractor and Integrated Services Company. It examines the unique environmental and logistical features of this project and how the alliance sought to deal with these critical issues utilising the strengths of the respective companies to reduce risks and ensure a cost-effective, successful operation. The logistical management of planning a rank wildcat in a remote location with no practical means of resupply and no local resources was further complicated by anticipated technical difficulties with the well.
The paper concludes by considering the different objectives of each company in conjunction with the overall project objectives and how these respective goals were aligned to the mutual needs of the alliance. The lessons learned by all three alliance members are noted and recommendations made on how they would approach such an operation in the future.
Unique PDC Bit Configuration Dramatically Improves Hole Cleaning, Drilling Efficiency in Low Hydraulic Applications
Authors: Hertzler G. J. , Wankier J. T. 
Published: December 2007

Abstract
A new PDC bit design, which arose from a formal alliance between a contractor and bit manufacturer, has dramatically improved bit cleaning and overall drilling efficiency in applications where only low hydraulic horsepower is available. The new design has been run successfully in the Denver-Julesburg Basin of Colorado where the efficient operation of downhole mud motors places limitations on the standpipe pressure and flow rates of drilling rigs. These limitations require bits be run under very low hydraulic horsepower, which until recently made it difficult to optimize drill bit performance.
This paper describes the development of a multi-port PDC bit that has improved penetration rates, overall drilling efficiency and economics in applications with very limited hydraulic horsepower. The new design, featuring an undercut shank, a new cutting structure/nozzle configuration and durable carbide supported edge (CSE) cutters, has shown dramatic improvement in drilling efficiency, cost-per-foot and bit life. Individual bits employing the new configuration have drilled more than 200,000 ft, while on the average, the new design has increased penetration rates some 21% when compared to the M3 32 bit used previously. The design process and field performance will be presented and analyzed.
The new PDC design is effective in applications were high hydraulic horsepower is unavailable. It is especially beneficial in soft formations, where efficient bit cleaning is of paramount importance.
Mud Lubrication—A Viable Alternative in Well Control
Authors: Grace R. D. , Burton M. R. 
Published: December 2007

Abstract
It is common in drilling operations to experience an influx during a trip. Generally, the drill string is partially or completely out of the hole. Under these conditions, it is common for the influx to migrate to the surface while decisions are being made as to the proper procedures, or arrangements for equipment and services are being considered. In some instances, the drill string becomes plugged during a kick and it is not possible to circulate the influx out of the hole in the classical procedure.
In instances where trips are involved, the well is under control when the trip commenced and control is lost during the trip. In routine cases, control can be regained by merely circulating and replacing the influx with mud. In situations where the drill string becomes plugged, regaining control is slightly more complicated; however, the same technology can be used. Under these circumstances there are generally several alternatives.
One alternative is to lubricate mud into the hole and bleed the influx to the atmosphere. This procedure is not often used. A seat-of-the-pants approach can be disastrous and a technical approach is not well understood by most field personnel.
Slimhole Completion & Production – What To Do After We Drilled The Well?
Authors: Kroell E. , Spoerker H. F. 
Published: December 2007

Abstract
Slimhole technology recently has been established as a proven alternative to conventional drilling operations. Now that the drilling community has shown that slimhole can reach the objective and is both technically and economically feasible, completion and production aspects of small wellbores receive the focus of increased attention. This paper discusses influences of the drilling process on later production performance of the well and focuses on currently available completion systems. A critical comparison between conventional drilling systems and their formation damage potential with slimhole-specific characteristics is given. Questions concerning production and workover strategies that sometimes are considered to be a barrier when deciding whether to apply or reject slimhole technology are presented. Economic justifications for selecting slimhole solutions during the drilling phase pf the well are critically weighed against the impact of possible production impairments during the total well life cycle.
Placement Properties of Foams Versus Gelants When Used as Blocking Agents
Authors: Nimir H. B. , Seright R. S. 
Published: December 2007

Abstract
In this paper, we investigate whether foams can show placement properties that are superior to those of gels, when used as blocking agents. Specifically, we examine whether the concept of limiting capillary pressure can be exploited to form a persistent, low-mobility foam in high-permeability zones while preventing foam production and formation damage in low-permeability zones. Using a C14.16 α-olefin sulfonate, we measured mobilities of a nitrogen foam in cores with permeabilities from 7.5 to 900 md (750 psig back pressure, 104°F), with foam qualities ranging from 50% to 95%, and with Darcy velocities ranging from 0.5 to 100 ft/d. We also extensively studied the residual resistance factors provided during brine injection after foam placement. The results from our experimental studies were used during numerical analyses to establish whether foams can exhibit placement properties that are superior to those of gelants. This study found that compared with water-like gelants, the foam showed better placement properties when the permeabilities were 7.5 md or less in the low-permeability zones and 80 md or more in the high-permeability zones.
Development and Field Testing of a New Low Toxicity Polymer Crosslinking System
Authors: Moffitt P. D. , Moradi-Araghi A. , Ahmed I. , Janway V. R. , Young G. R. 
Published: December 2007

Abstract
A low toxicity polymer crosslinking system has been developed which is tolerant of high brine salinity and hardness and has worked well in two field applications. The system involves the gelation of polyacrylamide with zirconium lactate; this is a lower toxicity system than the commonly used chromium gelling systems. Microgels prepared with the new polyacrylamide/zirconium system have been tested in two different field applications: 1) an injection well test in a large waterflood unit in northeastern Oklahoma, the North Burbank Unit, and 2) an injection well and a production well test in a waterflood unit in northern Texas, the C. B. Long Unit. In the injection well test in the North Burbank Unit, 69,000 barrels of polyacrylamide/zirconium gel were injected into an injection well. Pressure falloff tests before and after polymer gelant injection showed a reduction in fluid mobility by a factor of 5 to 6 as a result of the crosslinked polymer treatment. In the C. B. Long Unit, an injection well was treated with 65,500 barrels of microgel and injection profile surveys before and after the treatment showed a diversion of 55 percent of the injected fluid to a low permeability zone. Several offset producing wells responded to the polyacrylamide/zirconium treatment and incremental oil production has been in the range of 15 to 20 BOPD. The production well treatment in the C. B. Long Unit resulted in a reduction of the producing water-oil ratio.
This low toxicity polymer crosslinking system has been developed for in-depth diversion of injection fluid in a variety of applications. The polymer gelant uses a fairly low concentration of polymer and zirconium crosslinker so large volume treatments are economical. The polymer system is also tolerant to hard brines and low pH environments.
Depositional Facies and Diagenetic History: Keys to Reservoir Porosity, Quality and Performance, East Vacuum Grayburg-San Andres Unit, Lea County, New Mexico
Authors: Siemers W. T. , Tisdale M. G. , Hallenbeck L. D. , Howard J. J. , Prezbindowski D. R. 
Published: December 2007

Abstract
The East Vacuum Grayburg-San Andres Unit (EVGSAU) is located in the Permian Basin, Lea County, New Mexico. The EVGSAU was unitized in 1978 and has been under waterflood operations since 1979. C02/water injection (WAG injection) commenced in 1986. An interdisciplinary reservoir study was initiated in 1994 to integrate the unit's geological character and reservoir performance in order to optimize the C02/waterflood. This paper examines the sedimentologic and stratigraphic framework, lithologic character, pore system, quality and continuity, and architecture and internal geometry of the reservoir and their application to safeguarding prime C02 flood performance within the reservoir.
The Permian-aged San Andres Formation is composed of two major, eustatically controlled, upward-shallowing carbonate ramp sequences that contain multiple, anhydritic, dolomitized successions in which subtidal grain-rich lithofacies grade upward into peritidal, mud-rich carbonates and siliciclastics. A siliciclastic, lowstand tidal flat unit, the Lovington sand, caps the lower sequence and separates the formation into the Lower and Upper San Andres. Grainstones and packstones deposited as high-energy shoals and bars are the primary reservoir lithologies. Diagenetic processes critical to the development of good reservoir porosity and quality are; (1) early dolomitization of the carbonate section, (2) intense dissolution and alteration of anhydrite to gypsum, and (3) dissolution of dolomite. Four correlatable subtidal grain-rich intervals constitute the chief flow units and the only continuous waterfloodable intervals across the field. Relationships between the distribution of the subtidal grain-rich lithofacies, porosity content, anhydrite and gypsum abundances, and structural position exhibit considerable potential for mapping reservoir flow units and for defining reservoir quality within flow units.
This geological model provided the architectural basis for the reservoir simulation pattern model used to evaluate reservoir performance and to modify EVGSAU operating plans to ensure optimum flooding. The geological model helped determine; 1) Upper San Andres vs. Lower San Andres performance, 2) infill spacing within the Upper and Lower San Andres, 3) the potential for horizontal injection in the Upper and Lower San Andres, and 4) repressurization volumes required for the Upper San Andres.
Exploratory Data Analysis of Production Data
Authors: Jansen F. E. , Kelkar M. G. 
Published: December 2007

Abstract
Production data represent a source of information about the ongoing dynamic flow process in the reservoir. A proper analysis of these data might therefore give an indication of the relationships governing the fluid flow. Exploratory data analysis is one tool which can be used to extract the required information and to establish a statistical significance to the results. This paper presents a simple approach to examine the interwell communication and interference of a mature waterflood in order to identify and rank areas of potential improvement. Using this as a screening process we can identify areas with the best potential for further and more detailed studies. In addition some of the problems and limitations associated with analysis of production data are discussed.
Numerical Simulation of Multimechanistic Gas-Water Flow in Fractured Reservoirs
Authors: Chawathe A. , Ertekin T. , Grader A. 
Published: December 2007

Abstract
A two-phase, two-dimensional, dual-porosity, dualpermeability simulator is developed to study the effects of multimechanistic flow of gas and water through tight, fractured reservoirs. The formulation incorporates the Newton-Raphson procedure to linearize the set of highly non-linear partial differential equations. These equations are then solved in a fully implicit form to obtain pressure and saturation distributions within the fracture network and the matrix.
In this paper, we discuss the development of the multi-mechanistic flow simulator with respect to fractured systems. For the multimechanistic systems, higher flowrates and cumulative production are seen at early times. This is attributed to the higher drawdowns experienced by such systems. At late times, a "choking effect" is hypothesized to be responsible for higher cumulative production from systems experiencing multimechanistic flow.
Implementing CO2 Floods: No More Delays!
Authors: Lambert M. R. , Marino S. D. , Anthony T. L. , Calvin M. W. , Gutierrez S. , Smith D. P. 
Published: December 2007

Abstract
The window of opportunity for maximizing oil profitability and recovery is closing for many fields in the Permian Basin. With this in mind, operators can not afford to continue delaying carbon dioxide (C02) enhanced oil recovery during this prolonged period of low and flat oil price. Key learnings from over twenty years of CO2 flooding are: the window of opportunity is closing,CO2 floods significantly increase oil recovery and extend the life of a field,when total costs (developing, operating, CO2 purchases and processing) are compared to drilling and acquiring for reserves, CO2 flooding is competitive,CO2 prices have declined commensurate with crude prices,CO2 technology and expertise have advanced,the cycle time from reservoir evaluation to flood installation is greatly reduced, andthe CO2 supply is more than adequate to recover all the possible tertiary reserves identified in the Permian Basin.
With many waterflood programs approaching the end of their economic lives, hundreds of millions of barrels of oil will never be recovered if tertiary recovery projects continue to be delayed. Proactive operators must reexamine the benefits of CO2 flooding now.