bluuebunny/crossref_metadata_2025_split huggingface dataset:
Best Practices in the Allocation, Commissioning, and Maintenance of Ultrasonic Gas Leak Detectors
Authors: Naranjo Edward , Neethling Gregory A. 
Published: February 2011

Abstract
Ultrasonic gas leak detection (UGLD) is gaining broader acceptance in the oil and gas industry as a means for detecting combustible gas leaks. UGLD responds to high pressure leaks by measuring the airborne ultrasound emitted, which when detected by the sensor, provides a measure that is proportional to the leak rate. A principal advantage of the technology is that it does not require gas to be transported to the detector and provides coverage for a relatively large area, up to 20 m in radius, suggesting UGLD is suitable for detecting gas releases in open, well ventilated sections of offshore platforms.
Despite such advantages, the location criteria and commissioning and routine maintenance procedures for UGLD are not as well understood as those for conventional gas detectors. A reason might be that UGLD requires the establishment of an ambient ultrasonic background noise level to decide the alarm level and assist with selection of optimal location, a requirement that has no parallel with point IR or catalytic sensors. Location of ultrasonic gas leak detectors is also based on identifying the potential sources of leaks and taking into account acoustic reflections and interferences caused by continuous or short timescale background ultrasonic noise.
Such newness might be enough to give a few would be users pause. They may believe that UGLD is for people with high technical competence or that mapping, commissioning, and maintenance are best left to UGLD equipment manufacturers. Experience by one of the authors of this monograph suggests the contrary. Ultrasonic gas leak detection, for its reliance on ultrasound as a proxy for a gas leak, is a simple concept to understand. Over the course of over 3,000 installations during the last 10 years, offshore platform personnel have developed best practices that reduce the time and cost required for installing and commissioning ultrasonic gas monitors and that ease the burden on maintenance. In this report, we examine several of these procedures and highlight the simplicity of installation and maintenance of this method of gas detection.
First Ever Multi-stage Proppant Fracturing on an Openhole Horizontal Gas Well in Deep Natural Fissure Volcanic Reservoir in West China
Authors: Zhang Jing , Zhou Yikai , Zhang Jianhua , Wang Yong , Liu Hai 
Published: February 2011

Abstract
The Kelameili Gas Field in the Western China is a deep, naturally-fissured volcanic formation. The lithology, with significant degree of heterogeneity, varies from granite to tuff and breccia, has a low matrix porosity ranging from 4 to 10% and a permeability ranging from 0.015 to 0.026 md, and up to 984 ft in gross thickness.
Due to this low permeability proppant fracturing has been considered necessary on the conventional vertical well completions. However, the presence of natural fissures in the reservoir has often lead to the premature screenout of many treatments, resulting in lower than expected production.
The multi-stage proppant fracturing of DXHW-1 is a milestone for the operator due to: 1) The very first and the deepest horizontal well in a volcanic formation in China, been stimulated with a multi-stage proppant fracturing treatment; 2) The completion tubular and tools were designed for bottomhole pressure (BHP) up to 13,000 psi, and deepest coiled tubing (CT) cleanout (at 14,426 ft) was planned as contingency for any premature screenout.
This horizontal well was completed in five individual stages that were pumped continuously, one after the other, into the 2,454 ft openhole section using nine openhole isolation-packers. 341,270 lbs of 30/50 ceramic proppant was successfully placed into the formation, using a total of 7,981 bbls fracturing fluid. The well produced 35.3 MMscfd initially after the treatment and the production was stabilized at 17.65 MMscfd with wellhead pressure of 4,206 psi, which is four times higher than the average offset well.
The success of this treatment has supplemented additional 30% volume to the first gas station just from this single well, and also allows the operator to announce the discovery of an additional 3,637.4 billion ft3 of natural gas reserves in this field. Based on this success same completion model will now be used on future wells in the Kelameili Gas Field with several wells currently being planned.
LNG for Petroleum Engineers
Authors: Choi Michael S. 
Published: February 2011

Abstract
While remote parts of the world are awash with hundreds of trillions of cubic feet (Tcf) of natural gas, the industrialized West and emerging economies of the East can't get enough of the clean-burning, environmentally friendly fuel. The problem is transporting this compressible fluid long distances, across major bodies of water. For markets greater than 1,500 miles, liquefied natural gas (LNG) has proved to be the most economic option. By refrigerating natural gas (primarily methane) to -260°F (-162°C), thereby shrinking its volume by 600:1, LNG can be transported in large insulated cryogenic tankers at reasonable cost.
Natural gas liquefaction is a series of refrigeration systems similar to the air conditioning system in our homes consisting of a compressor, condenser and evaporator to chill and condense the gas. The difference is in the scale and magnitude of the refrigeration. A typical single-train LNG plant may cost $1.5 billion and consume 6-8% of the inlet gas as fuel. Since many of the impurities (water vapor, carbon dioxide, hydrogen sulfide, etc.) and heavier hydrocarbon compounds in natural gas will freeze at LNG temperatures, they must first be removed, and disposed or marketed as separate products.
This paper will provide an overview of LNG liquefaction facilities, from inlet gas receiving to LNG storage and loading.
However, the focus is on the liquefaction process and equipment. Differences among the commercially available liquefaction processes (cascade, single mixed refrigerant, propane-pre-cooled mixed refrigerant, double mixed refrigerant, nitrogen, etc.) will be discussed. The aim is to provide SPE members with a clear understanding of the technologies, equipment and process choices required for a successful LNG project.
Optimizing in Four Steps Composite Lost-Circulation Pills Without Knowing Loss Zone Width
Authors: Kefi Slaheddine , Lee Jesse C. , Shindgikar Nikhil Dilip , Brunet-Cambus Chrystel , Vidick Benoit , Diaz Nelson Ivan 
Published: February 2011

Abstract
A composite blend for controlling lost circulation has been developed on the base of a new four-step methodology. This blend exhibits superior performance over conventional treatments and eliminates missing loss-zone diagnosis and characterization.
Fighting lost circulation is a costly and time-consuming process. Conventional lost-circulation treatments try minimizing excess costs from rig time and fluid loss. In addition, they try avoiding the need for additional casing. However, these treatments are often based on trial and error without any practical technique to properly diagnose and characterize the loss- zone.
The new methodology addresses these shortcomings. The methodology proceeds in four steps: Dispersing a composite lost circulation material in a base fluid, Bridging the loss zone with fibers, Plugging the fiber networks, and Sustaining the plugs. Each step is parameterized by criteria, which can be optimized to meet the performance requirements. The fibers must possess certain form factor and exhibit specific physical properties to bridge open fractures after deploying through bottomhole assembly and drill bits. The composite plug also must endure pressure fluctuation during drilling or cementing and must tolerate erosion forces exerted by the fluid flow and downhole hardware. The four-step methodology provides an engineered combination of sized granules, stiff and flexible fibers. This new composite system was validated in several field trials in South America and Europe. In addition to the field trial results, this paper also describes the laboratory-scale and yard-scale tests, which were used for developing the new system. These tests helped establish guidelines for deployment through bottomhole assembly and drill bit.
These examples demonstrate that the novel composite blend system improves performance and robustness in curing losses compared with conventional single-fiber systems.
Demonstrating CO2 Sequestration as Part of a First Year Engineering Course
Authors: Neal P. R. , Ho M. , Fimbres-Weihs G. , Hussain F. , Cinar Y. 
Published: February 2011

Abstract
All engineering freshman at the University of New South Wales (UNSW) are required to complete the course "Engineering Design and Innovation". The course, commenced in 2006, provides students with learning opportunities in design, communication and teamwork. Each year, over 1,000 students combine lectures in design theory and communications skills with a hands-on design project. Ten of the schools in the Faculty of Engineering offer design projects as part of the course. The first project offered by the School of Petroleum Engineering was involved designing a "mini sucker rod pump". In recent years the School offers a project on CO2 sequestration - which has broader appeal and relevance to students across the faculty. Despite students’ enthusiasm to win the design contest, the aim of the course is to build skills rather than a device.
In this paper, we highlight the innovative approaches to demonstrating CO2 injection taken by UNSW first year students. We also evaluate the teaching and learning outcomes from this project. All teams worked together to design and build their device and to document their experience. However, some teams collaborated more effectively than others. We quantified this effectiveness using an online peer assessment tool that enables students to rate the performance of their team mates. We incorporated these ratings into the assignment of individual marks for group assignments.
We analyse the marks students achieved for various assessments and components of the course. We find that female students tended to out-perform their peers in both individual and team assessments. We also find that students who did well in individual components of the course also did well in the team components. We find it is hard to use early assessments to predict performance in later assessments. There is a strong connection between students’ results for their Design Proposal and their results for the Final Design work. We are able to show a statistically significant improvement for marks for presentations but not for report writing. We also found that there is an improving trend in marks over the semester. Having surveyed students, we find that 90% of students were satisfied with their experience of the course. Students found this course to be challenging and fun, giving them a good start in developing their skills as engineers.
Effect of Fracture Orientation on Induction Logs: A Modeling Study
Authors: Hu G. , Geldmacher I. M. , Liu R. C. 
Published: February 2011

Abstract
A common difficulty associated with fracture modeling is the need for a very fine mesh to simulate the detailed geometry of the fracture. Such a fine discretization in the 3D numerical model leads to a lengthy computation time; with tilting fractures complicating the problem further. In our work, we apply a novel technique that has recently been used in modeling non-conducting membranes in biological studies. This technique makes it practical to model even very thin fracture apertures.
The response of induction tools to fractures has been of interest to the oil industry for decades. Fractures are important indicators of formation characteristics. Several recent papers (Xue, et al., 2008 and Tang, et al., 2006) address vertical fractures intersecting a borehole wall in which the induction tool response was numerically simulated with 3D Finite Difference or Finite Element methods. However, in the cited publications, only vertical fractures were studied. In nature, fractures are not necessarily vertical and the wellbore can have an arbitrary inclination with respect to the fracture. The effect of fracture orientation therefore needs to be understood since it pertains to the nature of the fracture and the characteristics of the formation of interest. The innovative 3D Finite Difference simulation developed in this work reduces the size of the solution domain significantly and overcomes the challenge of geometry modeling in dipping, finite-length fractures. These breakthroughs allow us to look into the dipping effect of thin fractures accurately and efficiently. We look at the effect of a fracture with respect to dipping angle, fracture resistivity, aperture and length. As a result, we discuss the complications in the interpretation of induction logs influenced by fractures intersecting the borehole, both vertically and non-vertically.
Integrating Flow Simulation With Multi-Component Time-Lapse Seismic: Application to Postle Field CO2 EOR Project
Authors: Heris A. E. , Kazemi H. , Davis T. L. , Wehner S. 
Published: February 2011

Abstract
An improved understanding of flow behavior in older producing reservoirs, plus proactive reservoir management measures could lead to improving recovery efficiency. In this regard, one such measure is the use of time-lapse, multi-component seismic imaging to enhance the characterization of the reservoir's flow model. In this paper, we describe the application of this concept to a CO2 EOR project in Morrow sandstone in Postle field, Oklahoma, USA.
Production and injection in the Morrow sandstone will cause saturation changes and can influence reservoir pressure based on operating practices. These changes, in turn, affect acoustic and elastic properties of rocks, which are detectable by time-lapse seismic imaging. Coupling these changes into flow simulation improves our understanding of the reservoir heterogeneity and connectivity. A reservoir simulation model was initially built using available geological, petrophysical and engineering data. The fluid flow performance was compared against observed reservoir performance. Time-lapse seismic anomalies, which are indicative of permeability variation in the reservoir, have been used to better understand reservoir connectivity and improve the quality of the reservoir model. On the other hand, flow simulation results help geophysicists to better interpret the time-lapse seismic anomalies.
Results indicate that time-lapse seismic is capable of inferring the permeability field and can detect stratigraphic baffles in the reservoir. Additionally, it provides valuable inter-well information that can assist the history matching process and improve the quality of the reservoir model results. We also found out that although it is normally expected that the P-wave seismic anomalies show mainly the changes due to fluid saturation, our interpretation based on production / injection data and simulation study indicates that pressure changes can also affect the P-wave anomalies.
Our research results demonstrate that dynamic reservoir characterization and integration of flow simulation and 4D seismic is a viable method for building an integrated reservoir model that can be used to guide field operations and maximize recovery efficiency.
Pushing the Boundaries for Carbonate Productivity Estimations
Authors: Altunbay Mehmet , Bal Adrian , Bolle Luc 
Published: February 2011

Abstract
We propose a reliable methodology for evaluating and estimating productivity of carbonate reservoirs. Our methodology starts with a geological evaluation of image logs focused on locating fractures, quantifying the macro (vuggy) porosity and understanding the depositional and diagenetic environment. Porosity, below the image resolution, is partitioned by analyzing the acoustic and nuclear magnetic resonance (NMR) logs. These data are integrated with petrophysical evaluations by using conventional resistivity analysis conditioned with the fluid, pressure and mobility information gathered from a formation tester.
The crucial part of the analysis identifies vugs and their degree of connectivity using acoustic log, formation tester and NMR spectral data, which results in a p-factor. A reliable matrix permeability profile, responding to varying pore connectivity along the hole, is constructed by modifying the conventional NMR permeability with the p-factor. The modified matrix permeability profile is calibrated with the mobility data from the formation tester. Fracture identification and quantification of its permeability are achieved using Stoneley wave and NMR comparisons, and borehole image data. The resultant data set leads to productivity estimations by either handling fracture (if present) or matrix permeability in a dual permeability simulation or via a simple tank model. Timely estimations of carbonate reservoir productivity within weeks of data acquisition result in planning for appraisal or production wells and completion designs before SCAL results become available, early identification of test zones, and/or negating the need for production testing leading to sizable savings.
Equation-Of-State Modeling For Reservoir Fluid Samples Contaminated By Oil-Based Drilling Mud Using Contaminated Fluid PVT Data
Authors: Sah P. , Gurdial G. , Pedersen K. S. , Izwan H. , Ramli F. 
Published: February 2011

Abstract
Bottom-hole samples collected in well-bore systems using oil-based muds (OBMs) are likely to be contaminated by medium to heavy hydrocarbon fractions present in the OBM. PVT data measured for a contaminated fluid will not be representative for the clean reservoir fluid and such PVT data is hence often ignored by the operator, which means loss of a considerable investment. It would be valuable for the oil industry to have options for numerical cleaning of OBM contaminated reservoir fluids and to be able to carry out Equation of State (EOS) modeling and regression for a contaminated composition in a way that would allow PVT data for a contaminated fluid to be corrected to represent the uncontaminated fluid. This paper describes such a methodology, which is integrated with EOS modeling procedures for numerically cleaned reservoir fluid compositions. Thanks to this methodology PVT data for contaminated samples does not have to be ignored and oil & gas operators can justify investing in PVT analyses for contaminated fluid samples.
The paper details the process through which the available data can be utilized. The composition of the reservoir fluid is estimated from the composition of the fluid with a certain content of OBM contaminate. A regression procedure is afterwards applied using the available PVT data in order to ultimately develop an EOS model for the clean reservoir fluid. Compositional data and PVT data are presented for a real reservoir fluid contaminated with OBM. Since also data is available for the clean reservoir fluid, it has been possible to verify the validity of the suggested procedure. The numerical cleaning procedure does not require any non-standard laboratory data and the given method is also not restricted to any particular brand of OBM or well-type.
Electron Beam E-Beam Irradiation Improves Conventional Heavy-Oil Upgrading
Authors: Yang D. , Kim J. , Silva C. F. , Barrufet M. A. , Moreira R. 
Published: February 2011

Abstract
This paper presents the experimental and simulation study of E-Beam hydrocarbon upgrading process which shows the efficiency of E-Beam process and radiation energy transfer mechanism for single and multiphase fluid. Society's growing demands for energy results in rapid increase in oil consumption and motivates conversion of unconventional resources to conventional resources. There are enormous amounts of heavy oil reserves in the world but the lack of cost effective technologies either for extraction, transportation, or refinery upgrading hinders the development of heavy oil reserves. The traditional problem of conventional heavy oil upgrading is that it takes large amounts of thermal energy and expensive chemicals or catalysts to upgrade. Using E-Beam technology we may lower the energy requirement and reduce the use of specific chemicals or catalysts. The design of facilities can be simpler and will contribute to lowering the costs of transportation and processing of heavy oil and bitumen.
Probing Wettability Reversal in Carbonatic Rocks by Spatially-Resolved and Non-Resolved 1H-NMR Relaxation Analysis
Authors: Bortolotti V. , Macini P. , Mesini E. , Srisuriyachai Falan , Fantazzini P. , Gombia M. 
Published: February 2011

Abstract
The paper is addressed to help designing alkali/surfactant flooding Enhanced Oil Recovery methods. In particular, it has been verified that a polar interaction mechanism to change wettability of a carbonate rock from water-wet to oil-wet can be obtained by injecting adequate chemicals, and in particular a solution of oleic acid and non-polar oil, like dodecane used for laboratory experiments. It is worth recalling that wettability is a petrophysical property that directly affects oil recovery by controlling the location, flow and distribution of fluids inside the reservoir rock.
The study has been performed by combining spatially resolved and spatially non-resolved 1H-NMR (Nuclear Magnetic Resonance) information obtained on full-size cores (up to 7cm in diameter). In particular, spatially resolved quantitative NMR imaging maps (or Quantitative Relaxation Tomography, QRT) and spatially-non resolved (or Magnetic Resonance Relaxometry, MRR) analyses have been performed on full-size cores to track the process and to assess the quality of wettability reversal. Changes of relaxation time distributions and of T1 maps obtained in the experiments seem correlated with wettability changes measured after the chemical treatment, i.e., the contamination with a solution of oleic acid and dodecane. Although further investigations are needed, the combination of MRR and QRT seems a promising technique to correlate the traditional Amott wettability index with local values of T1 in internal sections of a rock sample.
In particular, the paper deals with the assessment and monitoring of wettability reversal of carbonate rocks used in laboratory studies to evaluate the efficiency of chemical Enhanced Oil Recovery methods, and in particular of alkali/surfactant flooding. The combination of 1H-NMR relaxation analysis, characterized by high temporal resolution, with quantitative maps, characterized by high spatial resolution, permits a better knowledge and the monitoring of the processes occurring inside the pore space leading to wettability reversal.