Day 1 Tue, November 30, 2021最新文献

{"title":"Reducing ABEX Uncertainties through Hybrid LSTK Contracting: A Factory EPSm Pilot Case Study in South East Asia","authors":"S. A. Canny","doi":"10.2118/208621-ms","DOIUrl":"https://doi.org/10.2118/208621-ms","url":null,"abstract":"\u0000 Well abandonment and the associated abandonment expenditure (ABEX) are necessary stages in the post cessation of production (Post COP) phase of the asset lifecycles. There are significant risk factors present, which vary in the frequency and severity based on a multitude of factors pertaining to environment, age, well construction techniques and stratigraphy, to name a few.\u0000 In the case of well isolation and abandonment operations there are opportunities to innovate through factory project execution techniques and commercial approaches, which are enhanced where standardization and commonality of well architecture is present. These techniques focus on reducing risk factors and creating value where conventional thought suggests there is marginal cashflow benefit, in asset retirement obligation expenditure. Through a reduction in the total cost of ownership (TCO), project financial performance below the estimated provisions, can unlock cashflow from relief adjustments on long term liabilities.\u0000 The Engineering, Procurement, Services management (EPSm) lump sum partial turnkey contracting approach was developed to assist operators in unlocking cashflow in ABEX provisions, through risk reduction via front end well engineering and integration of service provision, allied to fixed price lump sum contracting to control project cost creep due to unforeseen events.\u0000 A pilot project was undertaken in South East Asia, delivering 64 permanently abandoned wellbores in 38 consecutive days, representing over 8,300-man hours and over 3,500 operating hours. The EPSm contracting approach delivered lump sum partial turnkey well abandonment services in a high-volume factory well abandonment retirement environment.\u0000 Operations were executed through a dedicated jack-up drilling rig trimmed to an asset retirement specification to reduce OPEX and increase efficiency. The operational project framework implemented pre-abandonment offline operations prior to rig arrival, then simultaneous operations (SIMOPs) concerning 2 primary worksites: the wellhead platform weather deck and the jack-up rig cantilever. Standalone concurrent Phase I slickline operations comprising of two units, were performed offline on the wellhead platform with pressure control equipment to execute primary reservoir isolation operations. Phase II & III operations were executed above, on the jack-up rig cantilever through the drilling riser and pressure control equipment, executing the overburden and surface isolation operations, minimizing online operating time of the jack-up rig.\u0000 Key Learnings from the pilot project are presented, along with pilot project key performance indicators. The project learning curve, and human performance factors provide insights to areas where there are synergies and opportunities to further reduce risk and the total cost of ownership through an Engineering, Procurement, Services management (EPSm) contracting approach.","PeriodicalId":335246,"journal":{"name":"Day 1 Tue, November 30, 2021","volume":"48 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114041442","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":"Improving Biological Reefing Viability Index as a Predictive Tool for Assessment of Potential Reefing Site in the Tropical Shallow Offshore Environment","authors":"Y. Hii, M. H. Mohd, Mohd Izzat Mohd Thiyahuddin, M. A. Rahman, C. Tan","doi":"10.2118/208497-ms","DOIUrl":"https://doi.org/10.2118/208497-ms","url":null,"abstract":"The current study improved the predictive capability of the biological reefing viability index (BRVI) calibrated using local data. The prediction capability of the BRVI improved from 61% to 76% accuracy out of the 181 locations where the underwater videos available for verification. The BRVI includes corals larvae density, age of larvae at site, sea current, sea temperature, chlorophyll-a, water depth and sediment type to predict biological productivity of an area. Among the parameters, corals larvae density and age of the larvae are the most critical parameters that influent establishment of new biological ecosystem. The BRVI uses settlement of corals larvae as the precursors for the establishment of new habitats in the offshore environment because scleractinian corals is known to be able to form backbone of a new habitat in the environment. In this approach, the BRVI focuses on habitat creation instead of just being a fish aggregating device (FAD) when an artificial reef is deployed in an area. The BRVI can be used as a rapid screening tool to identified potential area for deployment of artificial reefs. The BRVI could reduce the chances of artificial reefs deployment that failed to address its objectives and intended outcomes.","PeriodicalId":335246,"journal":{"name":"Day 1 Tue, November 30, 2021","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123591423","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":"Challenges and Lessons Learnt Operating During Covid19 Pandemic in Remote Location: A Success Story of Mauritania Deepwater Abandonment and Decommissioning Campaign","authors":"S. Sellapan, M. S. M. Allapitchai, Ahmad Johan, El Khalil Mohamed M’Bareck Heboul, W. Liew, Ahmad Hafizi Ahmad Zaini, M. A. Abdul Razak, M. Y. Yaakub","doi":"10.2118/208460-ms","DOIUrl":"https://doi.org/10.2118/208460-ms","url":null,"abstract":"\u0000 Operator's Wells Abandonment & Decommissioning campaign consists of 15 Deepwater subsea wells in Field \"C\" offshore West Africa. Discovered in 2001, the field is located approximately 80 km west of coastline and about 90 km from Nouakchott, capital of Mauritania. Field \"C\" is a deepwater field in water depth ranging from 730m to 830m. The field was developed using subsea wells, Hinged Over Subsea Templates (HOST), manifolds, flexible flowlines, umbilicals, and risers tied back to a permanently moored FPSO. In total, the field consists of nine (9) oil producer wells and five (5) water injection wells. During the development stage, one (1) gas injection well was drilled and completed at adjacent Field \"B\" about 17 km Northeast of Field \"C\". The water depth at this gas injection well location is approximately 280m.\u0000 Field \"C\" reached maturity in 2016. Due to high operating costs, declining production coupled with declining oil prices, the decision was made to cease production, plug and abandon (P&A) and decommission the field. Two phases strategy was engaged by the Operator in order to complete the decommissioning and abandonment of Field \"C\". In Phase 1, which was executed back in the year of 2017-2018, all the 15 deep water subsea wells were temporarily suspended with two (2) barriers in place. The Floating, Production, Storage and Offloading (FPSO) unit was decommissioned and disconnected. In line with the strategy of dividing the project into two phases, the information on well integrity and conditions acquired during the Phase 1 Temporary Wells Suspension (TWS) was used by the Operator in planning for Phase 2 – Wells Plug and Abandonment (P&A).\u0000 The operator made full use of temporary well suspension period between Phase 1 and Phase 2 for engineering, procurement, and operations preparation. The same drillship was utilized for the project in both phases. Multiple optimizations and modifications were done on the drillship based on lessons learned in Phase 1 and to cater for the subsea Xmas Tree and subsea structures retrieval in Phase 2. Due to the nature of the remote location and no existing oil & gas operations support base, all equipment required in this project was sent to Mauritania early. Equipment inspection and acceptance were carried out in Mauritania as part of the strategy in ensuring the availability of good quality equipment for offshore operations. The operations on Wells Plug & Abandonment commenced in December 2019.\u0000 In March 2020, upon declaration of the COVID-19 pandemic, operator was faced with difficulty of continuing operation as the Host Country activated border lockdown. The operator managed to continue operations for remaining well and demobilized drillship and personnel safely. Operator has successfully retrieved three (3) subsea Xmas Trees, P&A three (3) wells and intervened six (6) other wells for tubing cutting before operations was suspended due to COVID-19 pandemic. Operator used the suspension phase to devise a ","PeriodicalId":335246,"journal":{"name":"Day 1 Tue, November 30, 2021","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130963711","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":"Case Study and Lessons Learnt for the 1St Fully Integrated Hwu Well Abandonment at Field a Offshore Malaysia","authors":"Shahril Yang Shahril Shahril, Tengku Khairul Izwan Tengku Ahmad Tengku Khairul Tengku Khairul, Khalieff Fathiee Lokman Zakey Khalieff Fathiee Khalieff","doi":"10.2118/208496-ms","DOIUrl":"https://doi.org/10.2118/208496-ms","url":null,"abstract":"\u0000 Uzma was awarded with 1st integrated well abandonment under Provision of Well Abandonment Integrated Services (WAISE) in 2018. Total of 22 wells were plug & abandonment with average 10 to 20 days per well were spent to complete the work. The scope of works is inclusive providing Project Management Team, Hydraulic Workover Unit, Accommodation Work Boat, Supply Vessels, and P&A services.\u0000 This paper will highlight the practical experiences and capture the lessons learned obtained executing 1st integrated well abandonment campaign in Field A Offshore Malaysia. This paper presents the overall project lesson learnt for 1st integrated well abandonment embarked from early stage of project planning, preparation, acceptance, technical, operation & project close out. The lesson learnt will be beneficial for all Operator & Contractor Company involving with integrated well abandonment. This paper also presents capability of hydraulic workover unit and recommendation for future of low-cost well's plug and abandonment.\u0000 Plug and abandonment operations with conventional hydraulic workover units have an enormous impact on low-cost plug and abandonment campaign in Malaysia compared with conventional drilling rigs. In essence, the lessons learned and insights gained throughout abandonment campaigns will keep accumulating with time to feed into the knowledge and experience vault. With proper project lesson learnt, many success cases and best practices can be emulated both from technical and commercial point of view. This lesson learnt will be beneficial for all Operator & Contractor Company involving with integrated well abandonment.","PeriodicalId":335246,"journal":{"name":"Day 1 Tue, November 30, 2021","volume":"16 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126233339","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":"New Approach to D&A Late Life Planning and Preparation: Era of Innovative Solutions","authors":"J. Lim, Mohd Izzat Mohd Thiyahuddin, Muhammad Arif Iskandar Ghazali","doi":"10.2118/208479-ms","DOIUrl":"https://doi.org/10.2118/208479-ms","url":null,"abstract":"\u0000 New approach to Decommissioning and Abandonment (D&A) during late life planning and preparation is essential to the Operators to make D&A a more affordable and sustainable aspect of the Oil & Gas (O&G) business. D&A of offshore structures is a necessary requirement in the life cycle of hydrocarbon production. Removal of the structural components of an offshore platform, including the topside and jacket, represents up to 20% of the total decommissioning cost. This includes removal and transportation of the platform structure, substructures and other materials for further remediation, e.g., disposal at onshore via scrapping, repurpose, reefing, etc. The objectives of this paper include reviewing the current methods and efforts in Malaysia to remove and transport end-of-life structures and to propose innovative solutions to optimize the structural removal cost in decommissioning.\u0000 The proposed recommendations consist of two categories; firstly, this research suggests improvements from the current available technologies and investigates more effective expenditure options on methods of structural removal. Secondly, this actionable insight explores novel solutions of maximising in-situ solutions. Few recommendations are proposed to be implemented in the platform decommissioning strategy. There is a huge Potential Value Creation (PVC) of adopting these recommendations as an attempt to reduce high cost of structural removal in decommissioning.\u0000 This paper presents an overall review of the current capabilities and available technologies in the region. Decommissioning in Southeast Asia (SEA) presents a unique challenge and opportunity compared to other parts of the world. Decommissioning capabilities in SEA possess a huge growth potential to match the maturity, in terms of experience and portfolio, of the D&A players in other regions such as Gulf of Mexico (GOM) and North Sea. This will improve as increasingly number of decommissioning projects will be completed by PETRONAS in the future. In addition, the distinct and rich marine ecosystems present great opportunities for various in-situ solutions to be maximized for the benefits beyond oil & gas applications.","PeriodicalId":335246,"journal":{"name":"Day 1 Tue, November 30, 2021","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122639770","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":"Plug and Abandonment for Gas Wells: A Case Study from Baghjan Oilfield, India","authors":"R. Bharadwaj, Bhavya Kumari, Astha Patel","doi":"10.2118/208461-ms","DOIUrl":"https://doi.org/10.2118/208461-ms","url":null,"abstract":"\u0000 The economic end of the life-cycle of a well is dynamic and it varies with the oil & gas market conditions and advances in extraction technologies. If production declines or the need for a workover arises, plugging and abandonment operations are followed. In case the wellsite has encountered accidental releases, systematic abandonment and remediation becomes even more crucial to avoid further environmental damage and capital investment. This paper analyzes the Baghjan oilfield blowout of the Assam-Arakan basin and provides abandonment practices for gas wells.\u0000 The mobile workover rig was stationed at the Baghjan Well-5 with the aim to plug the lower producing zone at 3871 m and complete the well in the upper Lakadong+Therria sand at a depth of 3739 m. Baghjan Gas Well No.5 blew during the temporary abandonment which was planned to mitigate the leakage in the wellhead. Improper depth for the placement of cement plug, failure to check the plug integrity, and shortcomings in the regular inspection of annular casing pressure led to the well control situation at the Baghjan gas well.\u0000 While pulling out the tubing conveyed perforation gun after perforating the Lakadong+Therria I+II sand, Shut-In Tubing Pressure of 4400 psi and 3900 psi Shut-In Casing Pressure was observed which indicated a leak in the Tubing Seal Assembly. The well was killed with a 9.76 lbm/gal sodium formate brine and in the middle of pulling the tubing, leakage in the W.F. Spool was identified which changed the priority of the operations. Therefore, a temporary abandonment operation was planned to mitigate the leakage problem in the primary and secondary seals, during which the well started flowing gas profusely after nipple-down of the blowout preventer. The shortcomings of the abandonment process can be conquered by the selection of an appropriate isolation material such as resin-based sealants or bismuth and thermite, which shall act as a primary barrier and provide enhanced zonal isolation. The isolation material should mitigate micro-fractures, minimize treatment volume and fluid loss, provide ample pumping time, and not degrade in the presence of wellbore fluids.\u0000 The study discusses resin-based sealants, cement slurry designs, advances in conventional, unconventional, and rigless abandonment techniques, and suggests the most efficient method for the temporary and permanent abandonment operations to avoid further such incidents in the oil and gas industry.","PeriodicalId":335246,"journal":{"name":"Day 1 Tue, November 30, 2021","volume":"150 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134012029","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":"Modelling Production Initiation from a Lazy Well by Direct Gas Injection at the Casing Head Using Dynamic Wellbore Simulator","authors":"Nashat. J. Omar, I. Al-Saeedi","doi":"10.2118/208488-ms","DOIUrl":"https://doi.org/10.2118/208488-ms","url":null,"abstract":"\u0000 This study deals with a lazy well completed with no packer in place. The main producing formation is showing strong signs of depletion where it lost more 2000 psig of reservoir pressure since the production started. Previous experiences in this well and other offset wells show there is demand for Nitrogen Injection Through Coiled Tubing Unit in the tubing in order to lift the well and bring it online whenever the well is shut-in for any reason. Direct natural gas injection at the casing head is a cost-effective alternative to rigless well lift operations. However, this is a challenging thing to achieve since it requires precise knowledge of injection rates and casing head pressure, additional to that formation fracture pressure and other reservoir characteristics should be taken into consideration. Data were collected and dynamic wellbore is created and linked to near well reservoir model to capture the transient behavior of the reservoir during start-up process. From Dynamic Modeling and simulation of the production system, best injection pressure, production choke, injection time and quantities are estimated and optimized for more efficient lifting process. After Initiating the well, production stability is observed in the transient simulator to ensure the success of the well lifting method. This method of production initiation is cost effective, and if implemented properly should bring the well back in production fast. Successful implementation this method demands a precise wellbore model to be created and shut-in surveys should be used to match the well status when it's not producing to tune the wellbore and fluid parameters.","PeriodicalId":335246,"journal":{"name":"Day 1 Tue, November 30, 2021","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133146652","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":"Mercury Contamination of Process and Pipeline Infrastructure - A Novel, All- Encompassing Solution for the Evaluation and Decontamination of Mercury from Pipelines and Topside Process Equipment to allow Safe Disposal","authors":"Stuart P. Baker, M. Andrew, M. Kirby, M. Bower, D. Walls, Lee Hunter, Alan Stewart","doi":"10.2118/208475-ms","DOIUrl":"https://doi.org/10.2118/208475-ms","url":null,"abstract":"\u0000 Mercury present in produced oil and gas will deposit onto the internal process infrastructure via a number of mechanisms including chemisorption and adsorption with the primary mechanism being through reaction with iron sulphide to form mercury sulphide. Due to the volumes of fluids produced and the length of time facilities are in production, even where the produced fluids have historically contained relatively low concentrations of mercury, pipeline scales containing percentage levels of mercury may be present.\u0000 Thus, aged facilities and infrastructure that have reached the end of their operational life and are selected for either recycling or abandonment, may pose a serious risk to health and the environment if the decommissioning process is not managed correctly. Smelting, hot cutting or other thermal/abrasive surface preparations for example, can lead to significant release of elemental mercury, a worker exposure hazard. Alternatively, if sub-sea pipelines are abandoned in-situ, all mercury present will ultimately be transferred to the local ecosystems. Consequently, the oil and gas industry have the requirement for a complete mercury decontamination solution from initial evaluation, demonstrable cleaning efficacy through to a guarantee for the treatment and disposal of the mercury waste generated in an environmentally-friendly manner.\u0000 In order to decide upon the most appropriate decontamination solution, an evaluation of the extent of mercury contamination should be undertaken. A novel approach that has recently been successfully implemented involved analysis of pipe sections by multiple analytical techniques, providing the mercury concentration in the scale/steel. From this, the total mass of mercury across the process or pipeline was approximated.\u0000 Subsequently, the efficacy of the preferred chemical to remove mercury from the internal surfaces of pipework was evaluated by chemical treatment of the pipe sections under laboratory conditions.\u0000 In-situ decontamination can be performed by a number of applications, including (i) the use of chemical pig trains in pipelines, (ii) closed loop circulation of chemical around topside process equipment and (iii) high pressure spraying of large surface areas such as storage tanks, FSO / FPSO vessels. The mercury waste generated is treated, on site or off site, to minimise the volume and disposed of in accordance with international regulations.\u0000 An all-encompassing mercury decontamination solution is described. Trials involving the chemical treatment of steel sections have demonstrated that more than 97% of the mercury deposited can be removed from the internal surfaces of pipelines and safely disposed of, significantly reducing the risk of (i) mercury release to the environment and (ii) worker exposure to mercury during smelting activities.","PeriodicalId":335246,"journal":{"name":"Day 1 Tue, November 30, 2021","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124784862","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":"Late Life Field Management with Instrumentation Failure. Modelling Predictions and Successful Validations of Late Life Subsea Gas Condensate System Using Historical Field Data","authors":"L. Lau, Kun An, Wu Jun Tong, Song Wang, Z. Yue, Jiang Nan Duan","doi":"10.2118/208484-ms","DOIUrl":"https://doi.org/10.2118/208484-ms","url":null,"abstract":"\u0000 Depleting reservoir pressure, increasing water cut and decreasing overall system production leading to increased liquid holdup are among the key challenges for typical late life gas condensate production system. This paper elucidates modelling details of a late life offshore subsea gas condensate system and how the findings are implemented and validated with actual field data for successful outcomes.\u0000 There is only one subsea well remain in operation with relatively long subsea flowlines. Subsea pressure and temperature transducers are out of service as the asset approaches the end of design life. In this context, flow assurance team has taken the modelling approach in order to minimize cost and to maximize values. Detailed transient multiphase thermohydraulics models are developed and benchmarked against field data. Historical field data over the past two years are utilized in order to predict the trend for key parameters such as well production rates and water to gas ratio (WGR).\u0000 Matrix of simulation including the predictions of slugging flow regimes are carried out for the entire flow path, from reservoir characteristics descriptions at bottom hole, through flow regimes analysis at topsides slug catcher. Three categories of operation characteristics, namely the low risk, medium risk, and high risk production periods are identified. It is predicted that the system would start to fall into slugging flow regimes from 2 months onwards with final production end date of after 10 months. This is shared with wider team such that operations and base management teams are informed with predicted multiphase flow characteristics for the remaining production life. As such, gas supply succession plan can be executed in time to ensure uninterrupted downstream commercial agreement. Feedbacks from operations team revealed accurate predictions of such analysis, including slugging flow phenomenon which was associated with flow and pressure fluctuations, was observed in field as predicted by the study. More importantly, the production cut-off date is accurately predicted 10 months ahead and within the accuracy of ± 1 week.\u0000 This study demonstrated how historical field data, coupled with detailed transient multiphase thermohydraulics modelling, can be utilized for offshore gas condensate production predictions during late life. Without transducers and/or virtual metering data feed, production end date can be accurately predicted based on key parameters analysis. This is particularly valuable for supply succession planning and is deemed a successful case study with significant positive outcomes which can be used as reference for other gas condensate assets.","PeriodicalId":335246,"journal":{"name":"Day 1 Tue, November 30, 2021","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124581828","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":"Annulus Perforate, Wash and Cement : Establishing Barrier Verification Process for Deepwater Subsea Wells Abandonment and Its Lessons Learnt","authors":"M. S. M. Allapitchai, Ahmad Johan, El Khalil Mohamed M’Bareck Heboul, S. Sellapan, W. Liew, Ahmad Hafizi Ahmad Zaini, M. A. Abdul Razak, M. Y. Yaakub","doi":"10.2118/208492-ms","DOIUrl":"https://doi.org/10.2118/208492-ms","url":null,"abstract":"\u0000 Wells plug & abandonment was carried out in a deepwater field (Field C) offshore West Africa. There were 15 deepwater subsea wells, in this field. Thirteen of the wells were completed with Open Water Vertical Xmas Tree (OXT) while remaining two were completed with Enhanced Vertical Xmas Tree (EVXT). All the wells were permanently abandoned with permanent barriers established in accordance to Norsok D-010, rev. 2013. This involved establishing well barriers which would both horizontally and vertically effective.\u0000 The operator evaluated several methods in establishing well barriers for the permanent abandonment purpose of these 15 wells. The barriers placement for areas with good annulus cement were straightforward as an internal cement plug could be spotted as a permanent barrier. For this particular field, it is noted that all of the 15 wells have hydrocarbon bearing and permeable formations above the top of expected annulus lead cement which is designed basically to manage ECD during cementing job rather than giving good annular isolation. Due to this, it is important for the operator to employ the best technique that could establish a permanent cement barrier both inside the casing and in the annulus at the same time. Operator learned that Section Milling was the widely accepted method to establish barrier in cases where there is poor cement or the annulus cement is not present particularly in land and offshore wells. However, this technique poses severe operational risk especially in a deepwater operation mode.\u0000 Upon review, it was determined that Perforate, Wash and Cement (PWC) technology has been proven and it would become a valuable technique in establishing well barrier which complies with abandonment requirement as per the industry guidelines. High risk activities for deepwater operations such as section milling could be avoided by employing this method. Nonetheless, the Perforate, Wash and Cement (PWC) technology has its own set of risks especially with its method of establishing the well barrier immediately upon setting it. This involves drilling and re-logging the well immediately after setting the cement in annulus to prove the barrier. Upon discussion with PWC contractor, it was agreed that the verification technique may create additional hazards as it could jeopardize the integrity of the installed barrier in the annulus. The additional requirement for cement verification process will also prolong the project duration, hence is an additional cost to the project too.\u0000 Operator worked together with the Perforate Wash and Cement (PWC) Contractor and Well Examiner to determine the best verification method for PWC plugs with the objective to comply with regulation on cement verification while at the same time, resulting in most cost-efficient and time-efficient operation. The establishment of Element Acceptance Criteria as an alternative Barrier Verification Process for PWC technology is necessary to improve the reliability of the sys","PeriodicalId":335246,"journal":{"name":"Day 1 Tue, November 30, 2021","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124616431","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}