bluuebunny/crossref_metadata_2025_split huggingface dataset:
Well Pressure Behavior of a Finite-Conductivity Fracture Intersecting a Finite Sealing-Fault
Authors: Escobar Freddy H. , Tiab Djebbar , Berumen-Campos Sergio 
Published: December 2007

Abstract
Hydraulic fracturing is important to the development of low permeability reservoirs. Recent advances in the technology of hydraulic fracturing, coupled with its economic success, have led to its application in high permeability reservoirs. Consequently, fracturing is now applied in all types of formations including highly faulted systems. The existence of a fault near a well may impede or contribute to the fracture extension process. Various models and techniques have been introduced in the literature for the interpretation of transient pressure behavior of vertically fractured wells. However, none of the current models and techniques has taken into account the case of a fracture intersecting a fault.
This paper presents a theoretical model for analyzing the pressure behavior of a finite-conductivity vertical hydraulic fracture intersected by a sealing-finite fault, considering different angles of intersection and neglecting in all cases wellbore and fracture storage effects. The point at which fracture and fault conjoint has also been a matter of analysis in this study. The model was solved numerically using PEBI grids.
For the case where the fracture-fault system form an angle of 90 or 75°, the pressure response is characterized by a maximum point or "hump" in the pressure derivative which takes place once the transient response of the fracture has vanished. This is because the fault delays the development of the pseudoradial flow regime. For smaller angles, a peak is not observed; however, there is a transition period that causes an apparent pseudoradial flow to develop earlier. This is because the hump tries to develop but the fault is not long enough for that to happen. When the fault is very long (LD &gt; re), pseudoradial flow does not develop because the fault acts as a boundary. A horizontal line on the pressure derivative curve is observed which can be easily confused with that of the actual pseudoradial flow regime. Correlations to estimate both fault length and fracture-fault angles are presented. A simulated example is presented to illustrate the proposed step-by-step procedure for interpreting a post-fracture pressure test of well near a sealing-fault.
Mercury and the Results from the Gulf of Mexico Offshore Operations Experiment (GOOMEX)
Authors: Boatman Mary C. 
Published: December 2007

Abstract
Surface sediment samples were collected from five platforms in the Gulf of Mexico during the Gulf of Mexico Offshore Operations Monitoring Experiment (GOOMEX), a Minerals Management Service funded study, and analyzed for total mercury. While this study was reported in 1995, new interest in the report was sparked by several newspaper articles using the results to link mercury in drilling discharges with mercury in fish. As part of the study program, sediment samples were collected from near the platform and far from the platform. Total mercury ranged from not detected to 3.5 parts per million in the sediments. The highest values were from near a single platform where discharges are shunted to within ten meters from the bottom. Tissue samples, including shrimp, crabs, fish livers, and fish stomach contents, were also collected as part of the project and analyzed for total mercury. Statistical comparison of the results indicated that the samples did not differ significantly between near field and far field. This presentation includes a background discussion of the issue of mercury as a global pollutant and puts into perspective the contribution from oil and gas activities around platforms.
Concentrations of Total Mercury and Methylmercury in Sediment Adjacent to Offshore Drilling Sites
Authors: Trefry John H. , Trocine Robert P. , McElvaine Michelle L. , Rember Robert D. , Hawkins Lucas 
Published: December 2007

Abstract
This paper presents results from a study of concentrations of total mercury (Hg) and methylmercury (MeHg) in seabed sediments near six offshore drilling sites in the Gulf of Mexico. Surface (0-2 cm) and subsurface (2-20 cm) sediment samples for this study were collected within three zones at each drilling site: &lt;100 m (nearfield), 100-250 m (midfield) and &gt;3 km (farfield). Total Hg levels in sediments from this study range from 11-92 ng/g (parts per billion, dry weight) for all farfield (background) samples and 25-558 ng/g for all nearfield samples. Concentrations of total Hg are significantly higher at nearfield stations than at farfield stations for five of the six drilling sites due to inputs from drilling discharges. Concentrations of MeHg range from 0.11-1.05 ng/g for all farfield sediments and &lt;0.03-2.7 ng/g for all nearfield sediments. In contrast with results for total Hg, concentrations of MeHg in surficial (0-2 cm) sediments from all six drilling sites do not vary significantly between nearfield and farfield stations. Statistical comparisons of MeHg levels in nearfield versus farfield sediments at the six drilling sites, along with data from two of those sites that show lower levels of MeHg in some nearfield sediments than in farfield sediments, suggest that elevated levels of MeHg in sediments around drilling sites are not a widespread phenomenon in the Gulf of Mexico.
Application of the API Compendium To Examine Potential Emission Reduction Opportunities for Upstream Operations
Authors: Ritter Karin , Nordrum Susann , Shires Theresa 
Published: December 2007

Abstract
In response to continued interest by its member companies about consistency in greenhouse gas (GHG) emissions estimation, the American Petroleum Institute (API) developed a Compendium of Greenhouse Gas Emissions Estimation Methodologies for the Oil and Gas Industry [1]. Initially distributed in June 2001, the Compendium is a result of more than a year long effort by API to screen, evaluate and document a range of calculation techniques and emission factors that could be useful for developing GHG emissions inventories.
In a continued effort to enhance the real-world application of the Compendium, API is examining the applicability of the Compendium methodologies to assess emission reductions from specific projects. This paper presents findings from this follow-on activity. Although the reduction activities presented may not be applicable to all locations, and the estimated emission reductions may not be achievable for all situations, the purpose of this study is to illustrate use of the Compendium and identify potential methodological issues. This paper examines technical considerations associated with estimating pre- and post-project emissions for a variety of emission reduction scenarios.
Discharge of Produced Water: New Challenges in Europe
Authors: Garland Emmanuel , Hjelde Erik 
Published: December 2007

Abstract
At present time, North Sea is the main offshore exploration and production (E&P) area in Europe. Due to ageing of the fields, produced water (PW) has now become the prime source of oily discharge to the marine environment from E&P activities.
So far, measures taken to regulate these discharges, at regional or national level, have focused chiefly on "dispersed" hydrocarbons. Although there is little evidence, if any, of harmful effect from PW actually discharged into the North Sea, when these discharges met the performance standard set up and are treated according to Best Available Technologies (BAT) as defined in 1992 by the Convention for the Protection of the North-East Atlantic (OSPAR), the pressure made by stakeholders has recently led regulators to take tougher measures regarding the "dispersed" hydrocarbons and to embark on the definition of additional, new prescriptive measures directed at other contaminants, such as chemicals used offshore and aromatic compounds.
During the last decade, tremendous research efforts have been made by the industry to design more efficient treatment facilities. As a result the 90's can be considered as the hydrocyclones decade, while the 2000's will see a wider range of techniques used, and the implementation of more preventive measures for reducing the overall load such as re-injection of PW or water shut-off techniques.
But the ongoing discussion on performance standards, and the competition for continuous reduction of the content of contaminants in PW at whatever the cost can be – even when it represents only a small percentage of the total input of contaminants in the North Sea – conceals two key questions: how clean is clean? How to set up the balance between additional measures, taking into account their cost, their efficiency, and the inevitable drawback of their additional impact on other compartments of the environment (CO2 emissions, energy and non-renewable resources consumption)?
To answer these two questions, it requires (1) a consensus on how to assess long-term effects of PW discharges and (2) that the issue is examined from a different point of view: the ecosystem, and its sustainability. Extensive research has been undertaken to develop tools for a better understanding and assessment of the long-term effects, while a new approach has recently emerged since the entry into force of Annex V of the OSPAR Convention, which should lead to the definition of Ecological Quality Objectives in the future. But this approach could be hampered by a recent initiative from the European Commission, which could lead to a total ban of produced water discharges by 2020. Notwithstanding, at present time, operators strive to encompass a holistic approach of water management.
Worldwide Drill Cuttings Injection Permitting Requirements and Guidelines
Authors: Guo Quanxin , Abou-Sayed Ahmed S. 
Published: December 2007

Abstract
Cuttings and other drilling waste injection through downhole fracturing started in the late 1980s and by the early 1990s, drill cuttings injection was being performed worldwide as an economically sound and environmentally safe long-term solution for drilling and production waste management. Although drill cuttings injection has become the preferred drilling waste management option in many parts of the world, each situation is different and the biggest hurdle in applying this technology for drilling and production waste management in some countries is waste injection permit application either because the regulatory agencies have not established any permitting requirements and application procedures or because the E&P operators are not familiar with the application process. Although different regions or countries have different permitting requirements, many of the requirements are essentially the same. This paper presents a review and analysis of worldwide drilling waste injection permitting requirements. Common permitting requirements are given with application procedure guidelines. The operators can use the guidelines to prepare their permitting application, while the regulatory agencies may use the review and guidelines as a reference for establishing or streamlining their own drill cuttings injection permit application requirements and procedures.
New Hydraulic Fracturing Fluid Technology Reduces Impact On The Environment Through Recovery And Reuse
Authors: Parker M. , Slabaugh B. , Walters H. , Weaver J. , Hanes R. 
Published: December 2007

Abstract
Hydraulic fracturing fluid systems are used to create the required fracture geometry and transport proppant into the fracture with a distribution that allows for the optimum performance of the well. Most systems currently use water-soluble polymers composed of guar or guar derivatives. Additional materials are used to optimize the fluid characteristics for the application and also to degrade the water-soluble polymer to make it easier to recover from the well prior to production. The recovered, degraded fluids cannot be used again and must be disposed of in a proper manner.
A new hydraulic fracturing fluid system has been developed that provides excellent performance during the fracturing process with post-fracture treatment fluid recovery approaching 100%. This fluid has the added benefit of being reusable after it is recovered following the treatment and prior to production. The benefits of reuse include the cost savings associated with capturing and reusing chemicals, the cost savings because of reduced water volume requirements for subsequent treatments, and the elimination of disposal costs. In addition, the total volume of chemicals required for fracturing operations is significantly less, thus reducing the demand on our environment.
Field analyses of the returned fluid determine parameters of maintenance and reconstitution for use in subsequent fracturing. This paper will outline the application of this fluid system, the concept for recycling and reuse, and the procedures necessary to properly use the recovered fluid in subsequent treatments.
Integrated Waste Management: Successful Implementations of Thermal Phase Separation Technology for Oil- and Synthetic-Based Cuttings and Drilling Fluid Waste
Authors: Antle Glenn , Gover P. , Pruett J. O. 
Published: December 2007

Abstract
Environmental legislation governing the disposal of drilling waste is continually restricting the discharge limits of drilling fluids and drill cuttings. Operators are charged with achieving a balance between minimizing the potential environmental impact of the drilling fluid while maintaining wellbore stability. Many reservoirs by their inherent nature, as well as the performance advantages of oil-based and synthetic-based drilling fluids, often preclude the use of a water-based fluid. The resultant oleaginous-based drilling fluid and cuttings, whether they are synthetic or diesel, present a complex and costly waste management challenge.
During the planning stages of a drilling project it is important to create an Integrated Waste Management Plan (IWMP). The IWMP takes into account the various types of waste generated by Exploration and Production (E&P) operations in a given area. The key feature of an IWMP is resource management. The use of thermal desorption technology as part of an IWMP allows the recovery and reuse of valuable liquids from the drilling waste. These recovered fluids can be reused as base fluid for reconditioning or building new drilling mud, or as a fuel source.
Spent materials from drilling, completion and workover operations represent the largest volume of waste typically included in an IWMP. These wastes include drilling fluids and/or cuttings from drilling operations. Due to more stringent environmental regulations with respect to hydrocarbon discharge limits, the use of thermal phase separation (TPS) technology helps operators meet their waste management goals in a cost effective and efficient manner. The economic benefit to the operator using TPS technology is greatly enhanced by the value and cost savings associated with the reuse of the recovered fluids.
Operator A selected TPS technology to provide drilling waste management and fluid recovery for a field development project in Blocks 10 and 12 in Ecuador. Operator B selected TPS technology for the Tengiz reservoir in Kazakhstan. TPS is a technology that recovers water, oil and other base fluids that would otherwise be transported for disposal. This paper describes the IWMP approach to the planning, designing and implementation of thermal treatment for these two distinct drilling operations in Ecuador and Kazakhstan. This paper will show how the synergistic approach to waste management enabled both operations to meet all environmental and operational objectives in terms of handling and disposing of drilling waste.
The IWMP approach has proven cost effective on many drilling projects around the world. The authors will chronicle the use of thermal treatment as part of successful waste management plans on drilling projects in an eco-sensitive area of Ecuador and in Tengiz, Kazakhstan. Similar projects are under consideration for Mexico, South America, Russia, and sites in the United States.
Manual Tubing Rotation Reduces Rod Pumping Failures by 76%
Authors: Hart Philip E. 
Published: December 2007

Abstract
A large Illinois oil field implemented the use of a new low cost manual tubing rotator in 25 marginal oil wells to reduce wear failures. Wear failures were indicated by "tubing splits" (Mechanical Wear1) or "corrosion occurring along a straight line due to corrosion inhibitor being wiped off from wear (Corrosion Due to Wear)". The failure rate was lowered from 203 repairs/year to 49 repairs/year (a 76% reduction) for "all failure mechanisms". Failures due to "Mechanical Wear or Corrosion Wear" were reduced from 108 repairs/year to 18 repairs/year (an 83% reduction). This success yielded over a 100% rate of return since the tubing rotator will normally pay out after eliminating the first pulling job and requires only 15 minutes per year of extra labor. Economics suggest that 100% to 20% investment rate of returns are achievable in wells failing once every 24 months or more often (not considering downtime losses). Thus, the manual rotator is not just for "problem" wells and significantly reduces wear failures.
Optimization of Acid Fracturing to Improve Heavy Oil Production in Naturally Fractured Carbonates
Authors: Wang Xugang , Zou Honglan , Zheng Xingquan , Zhang Fuxiang , Fan Yonghong , Cheng Xingsheng , Zhang Rusheng 
Published: December 2007

Abstract
This paper presents detail experimental and theoretical study and the results of successful applications of acid fracturing to enhance heavy oil recovery in Ordovician formation in LN region of TARIM, China. The Ordovician formation in LN field is extreme heterogeneous carbonate with naturally fractures. The reservoir temperature is 140 °C, and the formation fluid has API gravity of 8.
To optimize the acid system for this complicated formation condition, we first studied the reaction characteristic of gelled acid compared with straight acids at temperature ranging from 60°C to 140°C. Acid conductivity experiments were conducted with a unique conductivity instrument using limestone samples designed to simulate alternating stages of pad acid fracs and closed acidizing process. The original way to determine acid/rock reaction rate at high temperature is to extrapolate from low temperature test data. Our test has shown that the actual reaction rate at high temperature is much less than that obtained from the low-temperature data. Also, results show that gelled acid is 2.5 times more retarded than straight acid and the delayed nature of gelled acids is useful forgenerating longer etched fractures. Gelled acids also have higher viscosity than straight acid, which reduces fluid loss and friction pressure in acid fracturing applications.
Based on the experimental result, some novel approaches were used to evaluate stimulation and improve heavy oil production. FMI logging technique was used pre-and post-stimulation, which shows that fracture numbers and shapes were much different from theoretical reorganization. Three kinds of fractures were observed, including vertical fractures, horizontal fractures and inclined fractures. A theoretical model considering wormholing was used to evaluate pressure decline after acid fracturing. In order to minimize post-stimulation production decline rate in field, a new technique, mixing light oil with heavy oil at bottomhole condition, was introduced into this area to significantly improved oil mobility.
Field cases of applying the new approach of acid fracturing in the Ordovician formation in TARIM over five years are presented. The field cases show the improvements in production of heavy oil resulting from the comprehensive approach.
Cost-Effective Treatment Programs for Paraffin Control
Authors: Barker K. M. , Waugh K. L. , Newberry M. E. 
Published: December 2007

Abstract
Paraffin related problems of deposition, congealing oil and interface/tank bottoms cost the gas and oil industry hundreds of millions of dollars each year. Most of this money is spent without a clear understanding of the problems being experienced or their cost. If the real cost of a problem is not calculated before a treatment program is started it may not be possible to know if that program is cost effective. This paper will attempt to explain the difference between an inexpensive program and a cost effective program. Case histories will be presented.
Modeling and Validation of Hindered-Matrix-Fracture Transfer for Naturally Fractured Petroleum Reservoirs
Authors: Civan Faruk , Rasmussen Maurice L. 
Published: December 2007

Abstract
This paper presents the formulation, validation, and application of the improved matrix-fracture-transfer models for naturally fractured reservoirs based on presumed matrix block shapes. These models are derived for applications to primary oil and gas production by pressure depression and secondary oil production by water flooding of oil reservoirs by considering hindered-fluid transfer between matrix blocks and the surrounding natural fractures. The analytical solutions derived for special boundary conditions involving the typical laboratory tests using rectangular and cylindrical shape rock samples to represent the matrix blocks are verified with experimental data and the values of the characteristic parameters, such as the diffusion coefficient and skin coefficient and thickness, are determined.
The analytical models, workable equations, and straight- line data plotting schemes developed in this paper can be utilized for effective analysis and interpretation of laboratory experimental data using various shape reservoir rock samples. This allows for rapid determination of the characteristic parameters of the matrix-fracture transfer models for various shape matrix blocks, which are essential for prediction of oil recovery from naturally fractured reservoirs undergoing a water flooding process by means of a computer simulation. Although no confirmation was presented for single-phase oil or gas production by pressure depression because of the lack of experimental data, similar results are expected to hold by the present workable equations, because the single-phase flow description can be expressed in terms of the same dimensionless form as the two-phase flow description. Further, the single-phase flow description is more accurate than the two-phase flow description, because the latter has been approximated based on the constant-average capillary- diffusion coefficient assumptions to derive analytical solutions.