Day 4 Thu, November 15, 2018最新文献

{"title":"Real-Time Hydrocarbon Mapping by Time-Lapse Borehole Electric Tomography","authors":"P. Dell’Aversana, R. Servodio, E. Rizzo, P. Cappuccio, C. Carniani","doi":"10.2118/193183-MS","DOIUrl":"https://doi.org/10.2118/193183-MS","url":null,"abstract":"\u0000 Real-time mapping reservoir fluids distribution during hydrocarbon production, or during injection operation, represents a crucial issue and a big challenge at the same time. In this article, we present a new approach based on single-well and cross-well electric measurements. We use electrodes permanently installed on the well casing and electrically insulated from it. We tested our approach through a two-steps workflow. In the first step, we performed forward and inverse modelling on realistic production scenarios. In the second step, we acquired, processed and inverted real data acquired in laboratory, where we tested small-scale scenarios of hydrocarbon production. We acquired and inverted DC (Direct Current) data. Our objective was to reconstruct the variations of the 3D distribution of electric resistivity during the various phases of oil production. The retrieved models reproduced properly the experimental movements of fluids observed in our lab measurements. Finally, modelling and inversion of both synthetic and real data confirm that cross-hole DC method allows mapping reservoir fluid variations even in case of predominant metallic components of the well completion.","PeriodicalId":11079,"journal":{"name":"Day 4 Thu, November 15, 2018","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75401228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pushing the Limits of Coiled Tubing to Address the Challenges of Matrix Stimulation in Multi-Lateral Extended Reach Power Water Injector","authors":"H. Jassem, Naji K. Salman, R. Said, D. Ahmed, Kaisar Al Hamwi","doi":"10.2118/192637-MS","DOIUrl":"https://doi.org/10.2118/192637-MS","url":null,"abstract":"\u0000 In Middle East carbonate reservoirs, power water injector (PWI) wells are typically completed with long openhole laterals. The reservoir contact provides pressure support and enhances sweep efficiency in the low-transmissibility reservoirs. Due to the wells deviation and length, coiled tubing (CT) interventions are required to successfully enter and identify each lateral, as well as to remove formation damage by pumping the matrix stimulation treatment across entire laterals.\u0000 During such CT interventions, laterals are accessed thanks to a hydraulically operated lateral identification tool (LIT), while the stimulation treatment is pumped through a ball-drop-activated high-pressure jetting nozzle (HPJN). LIT and HPJN are efficiently operated by monitoring downhole pressure values both inside and outside of the bottomhole assembly, in real time thanks to CT fiber-optic telemetry. Those downhole pressure readings further assist in optimizing the pumping rate during the job, while keeping it below the fracturing pressure. Finally, the telemetry provides support for gamma ray (GR) logging, which facilitates depth control and lateral identification.\u0000 This study features a case history during which the matrix stimulation treatment was conducted in two separate CT runs for both laterals of the well. For the first run, the CT initially entered L-0 following the natural path of the well, whereas L-1 was accessed by activating the LIT. Correct lateral entry was confirmed by matching the acquired GR readings with reference logs. After successfully accessing L-1 and reaching its maximum depth, a ¾-in. ball was dropped to isolate the LIT and activate the HPJN for stimulation.\u0000 During the second run, as the CT entered L-0, GR monitoring was used to confirm lateral accessibility. The stimulation treatment was pumped after reaching maximum depth and isolating the HPJN. During the stimulation of each lateral, 20% viscoelastic diverting acid was utilized for diverting from high-intake zones and 20% HCl to stimulate damaged/tight zones.\u0000 This operation illustrates how downhole pressure gauge readings are used to sequentially operate the LIT efficiently and activate the HPJN, as well as to pump the matrix stimulation treatment below the fracturing pressure. Real-time GR readings, meanwhile, are used for depth control and to correctly identify laterals.","PeriodicalId":11079,"journal":{"name":"Day 4 Thu, November 15, 2018","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77846331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automated Multidisciplinary Collaboration in Integrated Reservoir Management IRM through Business Process Management BPM","authors":"M. A. Marzouqi, L. Saputelli, M. Abdou, R. Mohan, S. Pandian, Maryam Al Hammadi, Muhammad Navaid Khan, J. Cumming, J. Pires, Alvaro Escorcia","doi":"10.2118/193012-MS","DOIUrl":"https://doi.org/10.2118/193012-MS","url":null,"abstract":"\u0000 The objective of this work is to enable the collaboration of multiple disciplines in the performance reviews of reservoirs while establishing a culture of variance reduction and sustainable consistency in results delivery. This effort focuses on the performance management reviews of very large carbonate reservoirs where the number of wells and producing zones overwhelm engineers and organizations with data volume and complexity due to areal and vertical heterogeneity.\u0000 A novel Reservoir Performance Review (RPR) solution has been implemented across various offshore reservoirs units. RPR initiates all asset activities during reservoir performance reviews and allows the tracking of actions over the life of the reservoir.\u0000 RPR leverages data analytics to automatically compute reservoir health key performance indicators that allow prioritization of the technical work, extract and transform data from multiple data sources, deliver performance dashboards with diagnostic plot standardized across all assets and users providing an archive of information and knowledge from past reservoir performance reviews.\u0000 RPR leverages business process management and integrated visualization to assist in the identification and recording of opportunities, risks and actions, while providing control and management of the business processes.\u0000 The solution offers an innovative way to collaboratively gather, validate, analyze reservoir performance across the asset on a sustainable and cost-efficient manner while addressing more formal approval processes in order to garner approval or authorization for action. Some of the realized benefits include ensuring effectiveness in the execution of reservoir management, monitor variance between actual performance and expectation during the execution of projects; and ensure production sustainability and mitigate shortfalls proactively. RPR enabled the achievement of a consistent approach across all assets for all reservoir performance review processes, while improving efficiency through automation of data gathering and presentation and the identification of all underperforming reservoir, sectors and fields.\u0000 Reservoir management excellence is achieved by delivering immediate value on the opportunities identified during performance reviews which ensure short term profitability while preserving long term goals. Typically, operators are satisfied by meeting targets within certain tolerance. RPR ensures that performance excellence is achieved by considering all technical and business aspects.","PeriodicalId":11079,"journal":{"name":"Day 4 Thu, November 15, 2018","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89075130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Operating Integrity - The ADNOC Journey to Ensure Safe Production","authors":"Stephen Brown, R. Qureshi, J. Zijlstra","doi":"10.2118/193020-MS","DOIUrl":"https://doi.org/10.2118/193020-MS","url":null,"abstract":"\u0000 The Objectives of this technical paper are: To share ADNOC Group experience in creating and implementing a Code Of Practice (COP) for Operating IntegrityTo demonstrate the imperative and business case for Operating IntegrityTo present the challenges and critical success factors for successful implementation\u0000 The scope is all operational production and manufacturing sites across ADNOC upstream and downstream operating companies.\u0000 Operating Integrity is a strategic focus area within the ADNOC Operational Excellence program. It is an imperative within the Oil and Gas industry in order to Ensure Safe Production and optimise availability. Several catastrophic process safety incidents within the industry have demonstrated that poor risk management and a lack of good operating practices by site operators can lead to massive business and human costs. Operating Integrity addresses the root causes of major industry accidents such as: poor control of safeguarding overrides; poor Alarm management; ill-defined operating envelopes; lack of effective shift handovers; PTW control failures; not following operating procedures; lack of operator competency. Traditionally, these topics have received less focus than technical and design integrity, but should be considered equally important. Typically Operating Integrity is centered around human factors and therefore has its specific implementation challenges.\u0000 ADNOC has collaborated with experts in each operating company to write a COP for Operating Integrity by adopting good practice from the OPCO's and benchmarking these practices with the wider industry (LEAN approach). This in-house collaboration has achieved strong ownership and the fast track development of a fit for purpose COP, whilst enabling the creation of a tailored change management plan to ensure the effective roll-out, communication and compliance with the COP at all operating sites. The paper will further elaborate on the main elements contained in the COP, which can be summarized as: Competent people in all HSE critical roles all the time (even when others are on leave or at training)Operating all our facilities within up to date operating envelopesManaging risk resulting from any deviations from design or abnormal operating conditionsRationalising and knowing how to react to alarmsUsing the Permit To Work systems effectivelyClear, consistent and effective daily communications and shift handoversAccessible and up to date procedures which are followed consistentlyAccessible and up to date critical drawings and documentsReal time visibility of over-rides and inhibits and a procedure regarding how to respond to them\u0000 The paper will elaborate on the Critical success factors for ADNOC implementation of the COP, which include: Leadership CommitmentEffective communication about Operating Integrity to senior leaders, middle management and site operations teams (the latter via mandatory e-learning packages)Establishing a change management plan and governing ","PeriodicalId":11079,"journal":{"name":"Day 4 Thu, November 15, 2018","volume":"63 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89198646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal Degradation Kinetics of Epoxy Resins and Their Drilling Application","authors":"A. Al-Yami, V. Wagle, W. Jimenez, P. Jones","doi":"10.2118/192863-MS","DOIUrl":"https://doi.org/10.2118/192863-MS","url":null,"abstract":"\u0000 Epoxy-resin applications in oil and gas wells have significantly increased for remediation and sustained-casing-pressure mitigation because of its solids-free nature and excellent thermomechanical/bonding properties when used either as a single component or as a resin/cement-enhanced composite. Therefore, it is imperative to assess the formation and degradation of structures in cured epoxy resin at downhole temperatures, particularly because hydrocarbon production requires long-term wellbore integrity.\u0000 Differential scanning calorimetry (DSC) was used to determine the glass transition temperature (Tg) of the proposed resin system, and thermogravimetric analysis (TGA) was used to characterize the thermal degradation response by monitoring the resin specimens’ mass loss over time under controlled temperatures ranging from 300 to 680°F at atmospheric pressure. The thermal kinetic response based on TGA was then modeled using the Arrhenius equation to predict the resin lifetime under expected wellbore conditions. A uniaxial load frame Tinius Olsen tester was used to assess the mechanical response of the resin system under elevated temperatures.\u0000 For a resin system subjected to downhole temperatures of 263°F, the model predicts that reaching 10% mass loss by thermal degradation can take more than 160 years, which is beyond the operational life of the wells where the system is evaluated. This indicates that the investigated resin system provides long-term dependability that ultimately results in reduction of intervention/remediation costs, along with production maximization. Additionally, the resin mechanical properties were evaluated at different temperatures to assess their response to expected thermal loading, which resulted in competent barriers that can withstand the cyclic loads generated by continuous wellbore operations. This work also presents a case study in which an epoxy-resin-cement composite is used as an annular barricade to help prevent and reduce sustained casing pressure. The resin-cement composite was placed in the annular section as a chemical packer tailored to improve bonding to steel pipe, along with optimizing its mechanical response to cyclic downhole loads, which resulted in no up-to-date sustained casing pressure. Furthermore, Cement Bond Log (CBL) results further support the optimum annular integrity attained when utilizing a cement-resin composite as chemical packer for enhanced isolation and annular pressure buildup mitigation.","PeriodicalId":11079,"journal":{"name":"Day 4 Thu, November 15, 2018","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75283536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improve Operator Effectiveness to Facilitate Effective Collaboration","authors":"Livin Vincent Thalakkottur, Subhankar Dey","doi":"10.2118/193297-MS","DOIUrl":"https://doi.org/10.2118/193297-MS","url":null,"abstract":"\u0000 The paper reviews how traditional control room designs, automation & controls and operational practices have become obsolete. With demand and supply fluctuations in the region, operating teams often find it challenging to achieve organization goals and production targets. And although the control room infrastructure may go through upgrades, situational awareness often is not improved. Today's world is at haste to achieve results, frequently compromising quality. The truth is that there are unhappy stakeholders whose operating environment doesn't meet their expectations.\u0000 Today, with advanced technology and human-factors engineering, control rooms can be better designed to improve operator effectiveness. In general, this enables various stakeholders to make better decisions, faster. This text reviews how operator effectiveness and collaboration is improved by carrying out interactive brain storming sessions to understand user requirements, manage competency, apply management of change, analyze complexity in various roles and evaluate human machine interface, console & control room designs. Benchmark studies expose the gaps and direct the user's attention to actions needed to achieve best results. In addition, the authors discuss how smart collaboration can be applied to prototype tests and virtual Factory Acceptance Tests.\u0000 The authors note that middle-eastern culture for operator effectiveness and collaboration is a bit laid-back when compared to competitors in the global market. However, the outcome of the methods described in this paper, when applied to an organization driven by leadership, secured better results. This paper reviews similar methods adopted by organizations which experienced greater Return-On-Investment. Moreover, market fluctuations increase the need to optimize and standardize processes to aid faster and smarter collaboration.","PeriodicalId":11079,"journal":{"name":"Day 4 Thu, November 15, 2018","volume":"349 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79730024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated Geo-Modeling and Ensemble History Matching of Complex Fractured Carbonate and Deep Offshore Turbidite Fields, Generation of Several Geologically Coherent Solutions Using Ensemble Methods","authors":"A. Abadpour, Moyosore Adejare, T. Chugunova, H. Mathieu, N. Haller","doi":"10.2118/193028-MS","DOIUrl":"https://doi.org/10.2118/193028-MS","url":null,"abstract":"\u0000 History matching reservoir models has always been tedious as it involves many uncertain parameters and requires many trial and error iterations. Frequently the modifications introduced seem artificial and may destroy geological concepts, only one matched model is obtained and the forecast of such a model may quickly be invalidated by new data. Eventually imperfect models lead to imperfect decisions.\u0000 Assisted History matching with ensemble methods has received a lot of attention in the past decade. In this methodology with an ensemble of models the correlation between all uncertain model parameters and the selected production data is assessed and using this correlation the ensemble of the models are modified to reduce the difference between simulated and real historical data in an iterative manner.\u0000 Ensemble methods are recognized to perfectly perform on the continuous Gaussian parameters, but their application on discrete geological parameters like facies and rock types has been a challenge for several years. Different solutions proposed to tackle this issue showed the importance of integrated workflows and the implementation of an assisted history matching loop in close relationship with the geo-modeling tools.\u0000 After several years of research, an assisted history matching tool based on ensemble method has been developed in Total via the integrated platform of geo-modelling Sismage-CIG. This tool has been industrialized early 2016 with the first operational study performed on a giant gas field in the Middle-East.\u0000 Ensemble methods are known to be relatively insensitive to the size of the model, number of uncertain parameters to be handled, number of wells and the length of historical data, but the industrialization of the tool to operate on huge complex fields with very large number of the wells needed several rounds of code optimization using state of art algorithmic approaches.\u0000 This tool showed outstanding performance on several types of models such as turbiditic deep-offshore and complex fractured carbonate fields. The latest history matching study performed with this method on a Middle-East field modeled with a grid containing 20 million cells, around 200 wells and more than 25 years of production history, involved more than 130 million uncertain parameters in each realization.\u0000 The use of assisted history matching with ensemble methods allows not only to take into account cell by cell heterogeneities as uncertainty in a coherent manner but it also delivers an ensemble of hundred matched models which creates a huge opportunity for forecast and decision making process. Moreover all models fully respect the geological a priori knowledge and the duration of history matching study has been drastically reduced (weeks instead of months if not years) using much less manpower.","PeriodicalId":11079,"journal":{"name":"Day 4 Thu, November 15, 2018","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82068299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Considerations of Pipeline Crossing Design","authors":"Abdul Rahman El-Chayeb, D. Wang, F. Kamal, Oussama Takieddine","doi":"10.2118/192652-MS","DOIUrl":"https://doi.org/10.2118/192652-MS","url":null,"abstract":"\u0000 Pipeline crossings are an integral part of brown field developments and their design for shallow water conditions poses a number of challenges which require special considerations. Hydrodynamic stability and Vortex Induced Vibration (VIV) are typical examples. For both of these design aspects, there is no specific design criteria and methodologies dealing with crossings as is the case for pipelines resting of the seabed which, among other codes and standards, are covered by DNVGL RP F109 and DNVGL RP F105 for stability and VIV respectively. In the absence of specific design criteria, the industry have relied on interpretations of existing codes leading to crossing designs with varying failure probabilities and safety levels for different projects and different operators.\u0000 This paper discusses the main aspects of pipeline crossing design in shallow water conditions as is the case for the Arabian Gulf Region. In this region, the water depths could be close to the limits of applicability of the conventional design codes which were established based on experiences and considerations for other geographical regions. As a result, the design of crossings poses an engineering challenge as the calculated allowable span lengths tends to be short and the number of supports greater than what can be reasonably constructed for the pipeline to sit on all supports. The viability of using design criteria adapted from these codes for VIV is assessed using full dynamic simulations taking into account the compressive axial loads in the crossing. It is shown that for the short crossing spans, which are typical in the shallow water of the gulf region, the onset of any VIV will result in phenomenon which is called here \"crosswalking\". This crosswalking will result in a lateral displacement of the pipeline over the crossing sleepers resulting in an increase in the first natural frequency due to the reduction in axial compressive loads and the change in behavior from beam to shallow arch.\u0000 Implementing the analysis procedure discussed in this paper and taking into account the potential for crosswalking will help increase the length of the crossing spans. This increase can be to a level where the hyperstatic conditions can be eliminated and the crossings can be designed to be construction friendly. This will have direct cost and schedule impact on the execution of brown field developments where crossings constitute a major element of the project. It is hoped that further work will be done on studying the VIV of pipeline spans and crossings under axial compression as this area of pipeline engineering has not been fully explored and the focus of VIV research has been directed to risers which are always under axial tension.","PeriodicalId":11079,"journal":{"name":"Day 4 Thu, November 15, 2018","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82307126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and Testing of an LWD Ultrasonic Microimaging Tool: Field Test Results from the Middle East and Europe","authors":"G. Warot, Shawn Wallace, H. Mostafa, Eslam Elabsy, Davide Di Tommaso, Aly Abdelkarim, C. Ciuperca","doi":"10.2118/193055-MS","DOIUrl":"https://doi.org/10.2118/193055-MS","url":null,"abstract":"\u0000 Increased development of naturally and hydraulically fractured unconventional reservoirs from horizontal wells, drilled with oil-based muds, has created a need for high-resolution logging-while-drilling (LWD) borehole imaging tools capable of resolving fractures in this borehole environment. A new LWD ultrasonic borehole imager has been developed and tested to meet this need.\u0000 Borrowing from wireline ultrasonic imaging technology, a 250 kHz piezo-electric transducer was adapted to an LWD drill collar. The single transducer serves as both transmitter and receiver: transmitting an ultrasonic pulse, and measuring both the amplitude and two-way travel time of the acoustic reflection from the borehole wall. The LWD tool takes advantage of drill string rotation making a 360-degree scan of the borehole with a single fixed transducer. Finite element modeling and laboratory testing in artificial formations and a large limestone block were used to determine the spatial resolution of the image, as well as the sensitivity to downhole acquisition variables such as standoff, tool eccentricity, and mud attenuation. Prototype tools were then field tested in several horizontal wells to verify the functionality and image resolution under actual drilling conditions.\u0000 The borehole images from horizontal wells in unconventional and conventional reservoirs in the Middle East and the UK verified that tool responded as designed. These images, recorded in both oil-based and water based muds, revealed open and cemented natural fractures, drilling induced fractures and borehole breakout, fine-scale bedding, and other textural geological features such as vugs and stylolites. A variety of drilling-related borehole artifacts were also observed, including keyseats, stabilizer impressions in the borehole wall, tool marks from a rotary steerable tool, and gouges made by the bit rotating off bottom. The amplitude image proved more sensitive to fractures, bedding, and other geological features, while the travel time image, combined with input mud compressional velocity, provided a 360-degree borehole caliper image, showing the borehole size and shape.\u0000 Although high-resolution LWD electrical imagers have been available for years, these can only operate in conductive, water-based, muds. As most horizontal wells in both conventional and unconventional reservoirs are now drilled with oil-based muds, the development of a high-resolution ultrasonic imager capable of identifying natural and hydraulic fractures, fine-scale bedding, secondary porosity, and other small scale features in wells drilled with oil-based muds fills an important gap in LWD technology.","PeriodicalId":11079,"journal":{"name":"Day 4 Thu, November 15, 2018","volume":"13 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81239557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Diffusion Coefficient and Fracture Aperture in Coal using Micro-Computed Tomography Imaging","authors":"Xiao Lu, R. Armstrong, Meng Yuan, Yulai Zhang, P. Mostaghimi","doi":"10.2118/193003-MS","DOIUrl":"https://doi.org/10.2118/193003-MS","url":null,"abstract":"\u0000 Coalbed methane (CBM), also known as coal seam gas, is becoming an increasingly important energy resource in the global natural gas market. Gas transport in CBM reservoirs remains a crucial research topic that has not been fully understood. Two scales of gas flow are identified in coal cores: flow in fractures and diffusion within matrix. The diffusion process is quantified by the gas diffusion coefficient while flow in fractures is governed by fracture apertures. This paper aims to explore the diffusion process in coal using X-ray microcomputed tomography (micro-CT) imaging. The experiments are conducted at 100 psi effective stress to eliminate the impact of pressure. The images obtained are registered for visualisation and analysis of the diffusion process and comparisons of fracture. In the paper, the impact of increasing effective stress on fracture aperture is demonstrated. Also, the diffusion coefficient of Krypton in coal matrix is estimated and discussed.","PeriodicalId":11079,"journal":{"name":"Day 4 Thu, November 15, 2018","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77688013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}