bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experience with Formate Fluids for Managed Pressure Drilling and Completion of Subsea Carbonate Gas Development Wells
Authors: Carnegie A. W. , Omar M. , Colman G. , Supriyono H. 
Published: October 2013

Abstract
This paper reviews the outcome of the first-ever deployment of low-solids formate fluids for the managed pressure drilling (MPD) and overbalanced open-hole completion of two subsea gas wells in a highly-pressured carbonate reservoir. The field development plan required the use of low-solids well construction fluids to minimise formation damage and ensure maximum rates of gas production from the reservoir. The deployment of low-solids fluids was also required to minimise the amount of solids that would pass through the gas processing facilities on production start-up.
The high pressure of the reservoir required fluids of an equivalent mud weight of &gt;15 pounds per gallon (ppg) - 1.80 Specific Gravity (SG) to maintain well control. Previous drilling experience in the area suggested there was a high probability of losing large volumes of fluid to the reservoir while drilling conventionally in overbalance. The strategy adopted to mitigate the risk of massive fluid losses was to use a 12.7 ppg (statically and dynamically underbalanced) potassium / sodium formate drilling fluid in combination with MPD technology to control the level of overbalance through backpressure. The reservoir section of each well was successfully and safely drilled with the low-solids potassium / sodium formate fluid at 150 psi overbalance in less than 2 days at an average ROP of 15-17 metres/hour with no measureable fluid losses to the formation.
On reaching Total Depth (TD) the potassium / sodium formate drilling fluid was displaced to kill weight (15.1 ppg) low-solids cesium formate brine as the tripping fluid before running the 7" pre-drilled liner. The tripping fluid was then displaced to 15.1 ppg clear cesium formate brine for the upper completion operation. These open-hole completion operations in cesium formate brine took 67 hours for the first well and 72 hours for the second. Both wells cleaned up naturally at start- up and tested at gas production rates of &gt; 150 MMscfd, exceeding expectations by 50%.
The results of these trials confirm that low-solids formate brines used in combination with MPD can help deliver highly productive wells in fractured carbonate reservoir developments without incurring excessive fluid losses during drilling and without requiring acid stimulation. From an economic perspective this first-ever deployment of an underbalanced formate brine system for drilling a carbonate reservoir in MPD mode reduced costs by: -Eliminating lost circulation events and associated fluid losses-Allowing the use of a lower-cost (i.e. lower density) brine for drilling-Providing early kick and loss detection
It is concluded that the successful use of MPD with low-solids formate fluids in two subsea gas wells have provided a new cost-saving technique for safely drilling and completing high-pressure carbonate reservoirs that are prone to severe circulation losses.
US Shale Gas and Tight Oil Boom - The Opportunities and Risks for America
Authors: Madden Brian , Vossoughi Shapour 
Published: October 2013

Abstract
Shale gas and tight oil from unconventional deposits is now a very attractive target in the UnitedStates. Thanks to the technological revolution brought about by the combined use of horizontal drilling and hydraulic fracturing the US is now exploiting shale gas and tight oil formations in record numbers. The success of these exploitations were indicated in the most recent report released by the International Energy Agency (IEA) announcing the United States will overtake Russia as the biggest gas producer by 2015 and will become the largest oil producer by 2017.
The Energy Information Administration (EIA) estimates that the US has more than 750 trillion cubicfeet of technically recoverable shale gas, and estimates that there could be in excess of 24 billion barrels of on-shore technically recoverable tight oil resources. Already the Barnett Shale play in Texas produces 6 percent of all natural gas produced in the United States, and Leonardo Maugeri predicts the natural endowment of the initial Bakken/Three Forks American shale play could become a big Persian Gulf producing country within the United States on its own.
The risks concerning shale plays are the effects of hydraulic fracturing on the environment, whichisperceived as contributing to both land and water contamination among other health and community impacts. The pros and cons of this aspect will be scrutinized in this paper.
The analysis in this paper will examine the prospects of the major shale plays in the US and the technology being used to enhance the potential opportunities this boom has for American jobs and the economy. This paper will also review a series of federal laws governing most environmental aspects of shale gas and tight oil development, and the full range of environmental and health risks this potentialshale revolution may hold for the United States.
Clastic Reservoirs Productivity Index Estimation with Well Log Data
Authors: Kozhevnikov Dmitry , Kovalenko Kazimir , Deshenenkov Ivan 
Published: October 2013

Abstract
Fluid filtration and mass transfer processes description are the key issue of the geological modeling and oilfields development design for reservoirs with complex structure. The well log data interpretation results are the basis of reservoir characterization.
The advanced application of the effective porosity value provides description of reservoir properties for dynamic (absolute, effective and relative permeabilities, capillary pressures, free fluids) reservoir simulation. The outcome values of effective porosity and clay swelling index are properties, which confidently reflect filtration reservoir parameters.
It is stated that effective porosity determined with log data provides evaluation of relative/phase permeability values and hydrocarbon distribution in transition zones using capillary pressure models. The application of Buckley Leverett function for known effective permeability gives evaluation of oil share in production. It is established that effective porosity has strong correlation with productivity index for wide range of clastic reservoir rocks from different region. Thus, the determination of effective porosity from well logs is resulted in prediction of oil and water amounts in production.
The effective porosity determination with log data is complex task, which could be solved with NMR log or conventional log data interpretation. Authors of stated work developed petrophysical models and appropriate algorithms (adaptive log data interpretation) for effective porosity determination based on adaptation to well logging tools metrology and reservoir conditions. These algorithms provide determination of effective porosity values with conventional well logs (spontaneous potential log, formation density log, gamma-ray log, neutron log and sonic log). Proposed models of capillary pressure and relative/phase permeabilities are used in dynamic reservoir properties prediction algorithms. Dynamic properties are transferred in digital geological and hydrodynamic models for reservoirdevelopment process simulation.
The well log derived effective porosity is used for reservoir rocks productivity index prediction. Oil and water effective/relative permeabilities have close relation to effective and dynamic porosity and this fact provides determination of oil and water effective/relative permeabilities in reservoirs as well as oil and water amounts in production. Obtained results are applied for fluid filtration processes modeling and reservoir development technology design.
Integrated Unconventional Play Solution — A Case Study in Developing Very Thin Low-Permeability Gas Reservoir and Shale Gas Reservoir in Sichuan Basin, Central China
Authors: Qiang Jiang Yu , Run Peng Hai , Yang Yang , Halomoan Parlindungan Monris , Zhao Jing Kai , Wang Yue 
Published: October 2013

abstract
Exploration and production of unconventional reservoirs have been conducted in the Sichuan basin since the 1950s. In that time, the relatively thicker low-permeability (tight) gas reservoirs have been developed, and a very thin tight reservoir and a shale gas reservoir are now being targeted. An operator has planned to develop these unconventional reservoirs with long horizontal drilling combined with multistage hydraulic fracturing. However, the management of the subsurface uncertainties appears as the biggest challenge.
Since the basin rests in a major compressional tectonic area, the target reservoirs are very sensitive to abrupt structural dip changes and faulted standoffs. Precise landing and lateral placement of horizontal wells are critical to the success of this program. Advanced logging-while-drilling (LWD) acquisition and real-time data transmission have been applied to overcome these challenges. A new LWD imaging technology delivers high-resolution electrical borehole images, azimuthal gamma ray, and multidepth measurement of formation resistivity for well placement and fracture identification purposes in the thin tight gas reservoirs. A multifunction LWD formation evaluation delivers the elemental capture spectroscopy in addition to triple- combo measurements for well placement and real-time formation evaluation in the shale gas reservoir.
Based on these real-time data and advanced interpretation or analysis techniques while drilling, structural features including dips, faults, and fractures could be clearly identified. Improved elemental composition from elemental capture spectroscopy and enhanced formation grain density evaluation could also be obtained. As a result, the team has been able to accurately place the well and significantly reduce the probability of erroneous lateral placement and optimize the completion design and planning of the hydraulic fracturing staging and segmentations. The successful implementation of this solution has led to the conclusion that the very thin tight gas reservoir and shale gas reservoir can be profitably developed in Sichuan Basin.
A Simplified Model for Desorption Area Prediction in Coalbed Methane Reservoir
Authors: Xu Bingxiang , Li Xiangfang , Xu Hanbing , Haghighi Manouchehr , Du Xiyao , Yang Xinzhou , Chen Dong , Zhai Yuyang 
Published: October 2013

Abstract
Production forecasting, well spacing, and well pattern optimization are key tasks in coal-bed methane field development plan. Desorption area around a production well is an important factor in well performance and reserve estimation. Analytical models are found to be simple and practical tools for drainage area calculation and well deliverability in conventional reservoirs. However, up to now, we have found no such analytical model for coal-bed methane wells with two-phase flow in which the gas desorption in coal is the controlling mechanism while the water is flowing in the cleat system.
In this paper, we present a mathematical model to predict how the size of desorption area is changing with pressure propagation during gas and water production. The pressure profiles at different production stages are determined using diffusivity equation which is solved using the known method of "continuous succession of steady states". For the case of two- phase flow of gas-water system, the pressure squared concept is used for linearization in middle and late times, while the pressure concept is used in early times when water flow is dominated. We have combined pressure from the solution of diffusivity equation with the material balance equation in order to develop our predictive model which is applicable for vertical wells for both cases of with or without hydraulic fractures.
This model is verified by numerical simulation and is in excellent agreement with the numerical solutions. Furthermore, the developed model is applied in one coal-bed methane well group in Hancheng field in China. It is found that desorption area is expanded outward in elliptical shape and the area can be calculated by the gas production data. The results show that two sample wells in the group have interfered with each other after producing for 525 days.
Enhanced Magnetic Surveying Technique Allows Tight Target Requirements to Be Achieved While Maintaining Drilling Efficiency
Authors: Aziz Intan Azian , Mondali Mondali , Mohammad Mahzan B , Tajuddin M Taufiq , Sapidih M Firdaus , Amir M Syafeeq , Brahmanto Edwin , Subroto Bramanta 
Published: October 2013

Abstract
Enhanced Magnetic surveying technique was introduced to Field Q in Malaysia allowing the tight geological target requirements to be achieved without impacting the operator’s drive for drilling efficiency.
Managing wellbore uncertainty is a significant challenge in Field Q, West Malaysia, where the Subsurface Team defines tight reservoir targets to accommodate the uncertainties that they have in a long step out well. Accurate well positioning becomes crucial in this situation to allow the penetration of multiple small targets. Historical approaches would have involved either running gyro surveys (which introduce more risk and time to the drilling process), or having to "over engineer" the wells (by creating tortuous well paths and drilling on the line to achieve the small drilling targets) due to the uncertainties of standard MWD surveys. Both of these approaches are against the drive to continually improve drilling efficiency while reducing risks.
Magnetic surveying has become increasingly accurate and now provides a cost-effective alternative to gyroscopic surveys in real-time drilling applications. New techniques for identifying and compensating for these errors involve a better understanding of the natural variations in the earth’s magnetic field, and new methods of mapping local variations improve magnetic modeling. The enhancement involves a multi-station analysis technique that provides compensation for drillstring magnetic interference and further improved when used in conjunction with geomagnetic referencing, which takes account of localized crustal effects in the earth’s magnetic field.
With a Geomagnetic Referencing System in Field Q, magnetic survey reduced uncertainty by 60% on average compared to a standard MWD error model. The benefits from this real-time drilling surveying process also means drilling is more accurate, with a reduced need for correction runs, or post-drilling changes to the planned well trajectory.
Drill Pipe Riser Intervention System Successful Experience in Offshore West Africa
Authors: de Fonvielle Henri , Bordet Laurent , Campbell William , Susak Nenad , Marajh Mitra 
Published: October 2013

Abstract
While offshore intervention on subsea equipment is quite common, the increasingly deeper water operations require light weight intervention systems while meeting safe and stringent operating specification. For these new deep offshore challenges, the conventional risers are becoming a more costly and less desirable solution.
Starting with a recollection of the main drivers that motivated the development of drill pipe riser intervention systems (DPRISi), the paper details the technical and economical challenges in West Africa that have led to the design of such a solution. When non-productive time and financial aspects are taken into account, it makes sense to develop a dedicated system in order to provide fast and reliable intervention.
Depending on the field requirements, two different types of drill pipe riser systems using a proprietary double shoulder connection were used by operators. A first solution was developed in 1999 featuring a seal ring close to the external shoulder. Subsequently, a new solution featuring a gas-tight metal to metal seal on the pin nose was developed in order to address increasingly demanding and challenging operations.
Intensively used in West Africa since 1999, the solution using the seal ring has shown robustness and reliability while being used for several projects in Angola such as Girassol and Rosa and now GirRI. The paper draws a summary of these operations and the feedback on the field use and maintenance. Also it emphasises the successful qualification process for the metal to metal seal solution that has been used in offshore Nigeria since 2010 for the USAN project.
Stress Analysis of Hollow Sucker Rod Screw Thread Joint and Shape Optimization of Screw Thread
Authors: Suling Wang , Yang Gao , Fangchao Liu , Siyuan Wangyuning Huang 
Published: October 2013

Abstract
In recent years, the screw pump is used as a new artificial method for it has the advantages of less investment, simple device structure, conventional operation, obvious energy saving and strong adaptability. It could reduce the cost of production effectively and improve production efficiency. Now it has become the main method of oil field mining machine. With the maturity of the ground drive screw pump oil recovery technology, many new forms of injection-production technology gradually applied to the screw pump well, such as, the downhole double screw pump oil-water separation system. For the torque which load on the whole system increases considerably than conventional screw pump, Higher mechanical property requirement of the supporting hollow sucker rod is needed, the failure area mainly concentrated on the screw thread joint. The Stress analysis was applied to the 34 hollow sucker rod which is supported on the on and off attachment of the downhole double screw pump oil-water separation system. According to the stress analysis results, shape optimization was applied on the root shape of the screw thread, the stress distribution of the screw thead on hollow sucker rod joint was improved, the mechanical property of the screw thread joint of hollow sucker rod was improved.
Metal Foam Sand Control Screen
Authors: Pei Xiaohan , Shi Bairu , Chen Lin , Zheng Lichen 
Published: October 2013

Abstract
Metal foam is recently being applied in down-hole sand control. The open pore substrate has a very permeable structure, the porosity and the pore size of the metal foam can be varied in a large range to meet the sand control demand. The three dimension open pore of metal foam results a very permeable structure to prevent plugging risks. The open pore metal foam is wrapped around a cylindrical geometry perforated base pipe. The number of foam layers and the pore sizes can be varied in order to achieve optimum flexibility for different sand control applications.
The effects of pore size and relative density on the metal foam mechanical properties and the relationship between the pore size and the sand control size have been studied. This paper compares the sand control characteristics of metal foam with two different conventional mechanical sand control screens supplied by manufactory, under similar conditions, loads, and formation sand. The metal foam based sand control screen improves the sand retention, and reduces the flow resistance by 16.6%. The metal foam based sand control screen was successfully used in the Liaohe Oilfield in China.
Opportunities and Challenges of CO2 Flooding in Indonesia
Authors: Muslim A. , Bae W. , Permadi A. K , Gunadi Bambang , Saputra D. D , Widyaningsih R. , Gunadi T. A. 
Published: October 2013

Abstract
Indonesia’s oil production has been constantly decreasing since 1995 and it is in need of another way to increase it. The oil production has been dominated by primary and secondary recovery techniques, while tertiary recovery techniques have rarely been used. The OOIP has been estimated at 75 billion barrels, the cumulative production is about 23 billion barrels, and proven reserve is 4.04 billion barrels. Therefore, remaining reserve is 49.5 billion barrels and the EOR potential is approximately 3.3 billion barrels. Looking at this potential, there is an excellent opportunity to implement a new suitable EOR method in order to increase the oil production.
Most of Indonesian crude oil is medium to light oil, with some fields containing heavy oil. Many researchers have been studying about CO2 flooding by experimental or simulation. The result shows that some of oil fields are favorable for CO2 flooding. Several studies on CO2 miscibility pressure revealed that the pressure ranges from 2150 to 3200 psig. This paper discusses and evaluates the opportunities and challenges of CO2 flooding in Indonesia. CO2 can be obtained from natural sources, natural gas processing, power plant, refinery and petrochemical industries. CO2 generated from power plant, refinery and petrochemical are need carbon capture technology. Sources of CO2 from natural gas processing are approximately 132.5 MMscfd, oil processing 899.41 MMscfd and power plant 6.817,91 MMscfd. Based on sources of CO2, oil categories, remaining oil reserves and previous studies, CO2 flooding is favorable in Indonesia especially in Central Sumatra and South Sumatra. Some of the challenges should be considered, such as depleted reservoir pressure to achieve MMP, infrastructure for CO2 transportation and surface facilities to process CO2 (recycling) that are not available, and also the unavailability comprehensive data of CO2 from gas field.
Innovative PDC Bit Designs With Improved Cutter Technology Deliver Significant Performance Improvements in Arabian Deep Gas Applications
Authors: Teasdale P. , Holalkere Markandeya S. , Djaoui M. , Ahmad R. T. , Roberts T. , Herron A. 
Published: October 2013

Abstract
This paper details the step by step process undertaken by a dedicated focus group established to provide a solution to inconsistent drilling performance with the 16" section in two deep gas fields in the Arabian Peninsula. The paper reviews the analysis undertaken as well as focusing on new design concepts and improved technology introduced.
Drilling in these deep gas fields, especially the 16" sections has always been a challenge for Polycrystalline Diamond Compact (PDC) drill bits due to the complex lithology that consists of a variety of carbonates with high interfacial severity, abrasive sandstones and compact shales. Despite improving the ability to consistently drill the 16" sections in a single run over the past few years, the new challenge is further improve consistency and rate of penetration.
Having experienced inconsistent performance and a series of premature PDC bit failures in these applications over the last few years the vendor assembled an integrated project team to investigate the issue. This team carried out an in depth analysis of all the available field data and identified several key factors that were responsible for PDC bit damage, such as bit/BHA whirl, poor operating parameters and their associated vibrations, and the limited ability of existing PDC cutters to drill such formations.
The findings led to the development of a new PDC bit design solution with high lateral and torsional stability capable of drilling with high drilling efficiency, and the introduction of new cutter technology, along with optimised operating parameters. The successful implementation of the new drill bit and recommended drilling parameters have enabled the operators to more consistently drill these challenging 16"sections in a single run at higher ROPs than previously achieved. This has resulted in significant cost saving for the operator.