Arafa Al Harthy, Khalid Al Habsi, Khalid Al Hinai, Stuart Walley
The conventional well stimulation treatments have been used in the oil and gas wells for long time to remove formation damage or skin in order to enhance the well production and be able to achieve economic rates. Wireline Applied Stimulation Pulsing (WASP®) is a prominent new technology that is gaining more grounds in the well stimulation for oil producer and water injector wells. WASP® is an electro-hydraulic technology that generates repeatable, high power hydraulic pressure pulses downhole over the entire desired interval. The repeated pulsing stimulates the near wellbore area, breaks up scale and causing tensile failures in formation rock, thus creating mini fractures/fissures for new flow paths and removing formation damage or skin caused by scale, fines etc. that were blocking perforations, slotted liners, sand screens or gravel packs, resulting in improved inflow. Petrogas Exploration and Development recently conducted a WASP® campaign trial that is the first application in the middle east in four vertical wells in the south of Oman oil fields. The wells were Well-A, Well-B, Well-C and Well-D. The vertical wells were completed on the Gharif and Al Khlata sandstone oil reservoirs, which contain relatively medium oil with a viscosity range of 44-239 cP. All the pay zones were perforated, except for Well-B which was completed with gravel pack. The wells were completed with artificial lift including PCP pumps and beam pumps with polish rod strings. It was understood that the poor/low production performance of the candidate wells was due to the high skin, caused by the damaged gravel pack and plugged perforations. The WASP® tool specifications that was run for the treatments of the wells were 2.750" in diameter, and the length was approximately 11.6 m. The conveyance was on electrical wireline cable by using a standard logging truck. The results of the WASP® treatments jobs have shown mixed results but generally Well-A/B, Well-C and Well-D showed improvement in well performance and consequently in the oil gains. In fact, in Well-C in Aseel field had the highest production rate increased by more than threefold - a remarkable improvement. The other wells are still in the monitoring stage. The operation performance of WASP® treatments went smoothly without any operational issues or lost time in all the jobs. WASP® technology demonstrated that it is an attractive alternative method to the conventional well stimulation methods that involve the use of hydraulic fracturing and injection of acid, solvents and deimulsifiers. These conventional well stimulation methods have limitations in the treatment of the pay zone and operationally intensive. WASP® technology is proven to be more effective, safe (HSE compliant), less time consuming and thus cost effective. Petrogas is now considering applying the WASP® technology to the water injectors.
{"title":"The First Middle East Unconventional Well Stimulation Treatment by Applying WASP® Technology: Field Cases","authors":"Arafa Al Harthy, Khalid Al Habsi, Khalid Al Hinai, Stuart Walley","doi":"10.2118/195057-MS","DOIUrl":"https://doi.org/10.2118/195057-MS","url":null,"abstract":"\u0000 The conventional well stimulation treatments have been used in the oil and gas wells for long time to remove formation damage or skin in order to enhance the well production and be able to achieve economic rates.\u0000 Wireline Applied Stimulation Pulsing (WASP®) is a prominent new technology that is gaining more grounds in the well stimulation for oil producer and water injector wells. WASP® is an electro-hydraulic technology that generates repeatable, high power hydraulic pressure pulses downhole over the entire desired interval. The repeated pulsing stimulates the near wellbore area, breaks up scale and causing tensile failures in formation rock, thus creating mini fractures/fissures for new flow paths and removing formation damage or skin caused by scale, fines etc. that were blocking perforations, slotted liners, sand screens or gravel packs, resulting in improved inflow.\u0000 Petrogas Exploration and Development recently conducted a WASP® campaign trial that is the first application in the middle east in four vertical wells in the south of Oman oil fields. The wells were Well-A, Well-B, Well-C and Well-D. The vertical wells were completed on the Gharif and Al Khlata sandstone oil reservoirs, which contain relatively medium oil with a viscosity range of 44-239 cP. All the pay zones were perforated, except for Well-B which was completed with gravel pack. The wells were completed with artificial lift including PCP pumps and beam pumps with polish rod strings. It was understood that the poor/low production performance of the candidate wells was due to the high skin, caused by the damaged gravel pack and plugged perforations. The WASP® tool specifications that was run for the treatments of the wells were 2.750\" in diameter, and the length was approximately 11.6 m. The conveyance was on electrical wireline cable by using a standard logging truck.\u0000 The results of the WASP® treatments jobs have shown mixed results but generally Well-A/B, Well-C and Well-D showed improvement in well performance and consequently in the oil gains. In fact, in Well-C in Aseel field had the highest production rate increased by more than threefold - a remarkable improvement. The other wells are still in the monitoring stage. The operation performance of WASP® treatments went smoothly without any operational issues or lost time in all the jobs. WASP® technology demonstrated that it is an attractive alternative method to the conventional well stimulation methods that involve the use of hydraulic fracturing and injection of acid, solvents and deimulsifiers. These conventional well stimulation methods have limitations in the treatment of the pay zone and operationally intensive. WASP® technology is proven to be more effective, safe (HSE compliant), less time consuming and thus cost effective. Petrogas is now considering applying the WASP® technology to the water injectors.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84619419","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}
T. Bérard, A. Gisolf, J. Desroches, Hemant Gurav, N. Chugunov, R. Prioul
We applied a recently introduced method to complete a feasibility assessment and design a stress testing campaign in a deep-water field in West Africa. We first reviewed the previous—and unsuccessful—campaign. Test data were inverted together with a priori knowledge from an independent geomechanical study to develop an understanding of the ambient conditions. Based on this understanding, the current campaign's chance of success (COS) was estimated to be 10%, with 1,000 psi of pressure capacity lacking to reach 95%. By analyzing the sensitivity of the risk to formation properties and design parameters, we identified various options to prevent this high, yet seemingly controllable, risk of test failure. Among them, a 1.7-ppg increase of mud density, expected to increase the COS to 80%, was deemed most effective and implemented. With 4 successful tests out of 10, the second campaign was more successful than the previous one. Yet this success rate was lower than anticipated. We inverted the second campaign's test data to revise our understanding of the in situ conditions. Our main findings are that, for this particular case, (i) the magnitude of the minimum horizontal stress was significantly higher than initially thought, (ii) the minimum horizontal stress and the horizontal stress ratio appeared to be anticorrelated, and (iii) the COS was extremely sensitive to the minimum horizontal stress. The conditions solved using the second campaign's dataset also explained the first campaign's negative outcome. This case study demonstrates that (i) the proposed planning method enables return of experience to be captured and leveraged from one test, or one series of tests, to the next, and the design of formation stress tests to be optimized, leading to an improved success rate of formation stress tests; and (ii) the proposed inversion scheme allows insight to be gained from both successful and unsuccessful tests, including in formation conditions other than the minimum horizontal stress.
{"title":"Quantitative Risk Management Improves the Success Rate of Micro-Hydraulic Fracturing Stress Tests","authors":"T. Bérard, A. Gisolf, J. Desroches, Hemant Gurav, N. Chugunov, R. Prioul","doi":"10.2118/195008-MS","DOIUrl":"https://doi.org/10.2118/195008-MS","url":null,"abstract":"\u0000 We applied a recently introduced method to complete a feasibility assessment and design a stress testing campaign in a deep-water field in West Africa. We first reviewed the previous—and unsuccessful—campaign. Test data were inverted together with a priori knowledge from an independent geomechanical study to develop an understanding of the ambient conditions. Based on this understanding, the current campaign's chance of success (COS) was estimated to be 10%, with 1,000 psi of pressure capacity lacking to reach 95%. By analyzing the sensitivity of the risk to formation properties and design parameters, we identified various options to prevent this high, yet seemingly controllable, risk of test failure. Among them, a 1.7-ppg increase of mud density, expected to increase the COS to 80%, was deemed most effective and implemented. With 4 successful tests out of 10, the second campaign was more successful than the previous one. Yet this success rate was lower than anticipated. We inverted the second campaign's test data to revise our understanding of the in situ conditions. Our main findings are that, for this particular case, (i) the magnitude of the minimum horizontal stress was significantly higher than initially thought, (ii) the minimum horizontal stress and the horizontal stress ratio appeared to be anticorrelated, and (iii) the COS was extremely sensitive to the minimum horizontal stress. The conditions solved using the second campaign's dataset also explained the first campaign's negative outcome.\u0000 This case study demonstrates that (i) the proposed planning method enables return of experience to be captured and leveraged from one test, or one series of tests, to the next, and the design of formation stress tests to be optimized, leading to an improved success rate of formation stress tests; and (ii) the proposed inversion scheme allows insight to be gained from both successful and unsuccessful tests, including in formation conditions other than the minimum horizontal stress.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89316894","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}
3D wide azimuth seismic data plays a vital role in fault interpretation, which has significant importance during exploration and development stages. Interpreting faults in 3D seismic data is one of the most time consuming and challenging process especially when dealing with poor quality seismic data. This paper provides a complete workflow and example of its application from seismic pre-conditioning to fault detection and extraction automatically based on published concepts by Dave Hale. With recent advancement in computer technology, multi-threaded algorithms and data driven methodologies, geoscientists can automatically detect and interpret virtually all discontinuities in seismic data in an efficient manner. This workflow involves random and coherent noise suppression, seismic likelihood attributes generation to enhance the discontinuities, detect faults and extract them from thinned fault likelihood volume. Unlike other fault tracking methods that use local seismic continuity attributes, such as coherency, this automated method incorporates aspects of Hale's fault-oriented semblance algorithm, which highlights fault planes with unprecedented clarity. This methodology has been successfully applied on complex faulted reservoirs. It contributes to the extraction of detailed discontinuity information (minor and major) from 3D seismic data. The traditional manual interpretation step that follows the detection of faults was time consuming and error prone. Automated fault interpretation improves the fault tracking accuracy, consistency and significantly reduces fault interpretation time in prospect generation. This workflow will optimize and reduce uncertainty associated with the seismic fault interpretation process.
{"title":"The Impact of Automated Fault Detection and Extraction Technology on Seismic Interpretation","authors":"A. Al-Maskeen, Sadaqat S. Ali, Muhammad Khan","doi":"10.2118/194819-MS","DOIUrl":"https://doi.org/10.2118/194819-MS","url":null,"abstract":"\u0000 3D wide azimuth seismic data plays a vital role in fault interpretation, which has significant importance during exploration and development stages. Interpreting faults in 3D seismic data is one of the most time consuming and challenging process especially when dealing with poor quality seismic data. This paper provides a complete workflow and example of its application from seismic pre-conditioning to fault detection and extraction automatically based on published concepts by Dave Hale. With recent advancement in computer technology, multi-threaded algorithms and data driven methodologies, geoscientists can automatically detect and interpret virtually all discontinuities in seismic data in an efficient manner.\u0000 This workflow involves random and coherent noise suppression, seismic likelihood attributes generation to enhance the discontinuities, detect faults and extract them from thinned fault likelihood volume. Unlike other fault tracking methods that use local seismic continuity attributes, such as coherency, this automated method incorporates aspects of Hale's fault-oriented semblance algorithm, which highlights fault planes with unprecedented clarity.\u0000 This methodology has been successfully applied on complex faulted reservoirs. It contributes to the extraction of detailed discontinuity information (minor and major) from 3D seismic data. The traditional manual interpretation step that follows the detection of faults was time consuming and error prone. Automated fault interpretation improves the fault tracking accuracy, consistency and significantly reduces fault interpretation time in prospect generation. This workflow will optimize and reduce uncertainty associated with the seismic fault interpretation process.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87131651","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}
Drilling operations generate much information, such as daily drilling reports and reports generated by service companies, support personnel, and other stakeholders. These reports can be unstructured with information presented in a variety of formats. The extraction of this information is frequently challenging, which limits its use in future projects. Natural language processing provides an efficient way of mining and obtaining knowledge. This paper demonstrates how these techniques were used to analyze vast amounts of historical documents to quickly rank well complexity and determine which aspects of drilling operations were most critical. Sentiment analysis can be used to classify documents and other pieces of information into separate categories. In social media, it is used to analyze the collective perception of a given trending item. The technique was used here to classify wells into two ranked categorized lists. First, a classification listed wells by drilling issues. Second, a complexity ranking was defined so that each well could be classified as easy or difficult to drill. To build the sentiment analysis tool, a random set of training wells and their respective documents were selected. From these documents, a list of words was identified in what became known as highlighting sessions. During these sessions, subject matter experts (SMEs) classified words found in the documents. This "bag of words" was then used to train a classifier capable of ranking the wells related to the documents. A probability was associated to each well, providing a likelihood of inclusion in a given category. The methodology proved to be successful, ranking drilling documents in both defined category sets. Results show that the list of ranked wells can be used by SMEs to identify which wells are relevant and deserve detailed analysis. The list generated for both categories provided a guideline for further analysis, particularly identifying wells with little value. Results also showed the importance of correctly developing a list of words, an adequate training set, and the language used, as well as the need for SMEs to produce the final analysis. The technology showed promising results with real-world applications being conceivable with its current level of maturity. However, the results also indicated room for improving its effectiveness by refining the highlighting sessions, word lists, types of classifier used, and final ranking methodology. The use of methods and technology to help improve and enable the analysis of unstructured data in the drilling space should increase over time. This paper shows how current technology can already be used in practical real-life cases to produce tangible value.
{"title":"Implementing a Drilling Reporting Data Mining Tool Using Natural Language Processing Sentiment Analysis Techniques","authors":"P. Kowalchuk","doi":"10.2118/194961-MS","DOIUrl":"https://doi.org/10.2118/194961-MS","url":null,"abstract":"\u0000 Drilling operations generate much information, such as daily drilling reports and reports generated by service companies, support personnel, and other stakeholders. These reports can be unstructured with information presented in a variety of formats. The extraction of this information is frequently challenging, which limits its use in future projects. Natural language processing provides an efficient way of mining and obtaining knowledge. This paper demonstrates how these techniques were used to analyze vast amounts of historical documents to quickly rank well complexity and determine which aspects of drilling operations were most critical.\u0000 Sentiment analysis can be used to classify documents and other pieces of information into separate categories. In social media, it is used to analyze the collective perception of a given trending item. The technique was used here to classify wells into two ranked categorized lists. First, a classification listed wells by drilling issues. Second, a complexity ranking was defined so that each well could be classified as easy or difficult to drill. To build the sentiment analysis tool, a random set of training wells and their respective documents were selected. From these documents, a list of words was identified in what became known as highlighting sessions. During these sessions, subject matter experts (SMEs) classified words found in the documents. This \"bag of words\" was then used to train a classifier capable of ranking the wells related to the documents. A probability was associated to each well, providing a likelihood of inclusion in a given category.\u0000 The methodology proved to be successful, ranking drilling documents in both defined category sets. Results show that the list of ranked wells can be used by SMEs to identify which wells are relevant and deserve detailed analysis. The list generated for both categories provided a guideline for further analysis, particularly identifying wells with little value. Results also showed the importance of correctly developing a list of words, an adequate training set, and the language used, as well as the need for SMEs to produce the final analysis. The technology showed promising results with real-world applications being conceivable with its current level of maturity. However, the results also indicated room for improving its effectiveness by refining the highlighting sessions, word lists, types of classifier used, and final ranking methodology.\u0000 The use of methods and technology to help improve and enable the analysis of unstructured data in the drilling space should increase over time. This paper shows how current technology can already be used in practical real-life cases to produce tangible value.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85404011","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}
G. Garcia, H. duMond, V. Mishra, L. Chen, Ron Hayden, C. Babin
A concept platform integrating the precise movement of a linear or azimuthal actuator, such as in instrumented wireline intervention tools (IWIT), with fast pressure measurement is presented. This device is intended to accurately move a measurement probe or sampling assembly either in the longitudinal or azimuthal direction in the wellbore to significantly improve data quality and operational efficiency. Precise movement control enables acquiring data at exact intervals to eliminate errors induced by cable stretching, overpulls, or variable cable creep. Monte Carlo simulations of this concept using current IWIT capabilities suggest significant reduction of the pressure gradient uncertainty over common wireline protocols. The operational procedure includes correlation using standard wireline gamma ray logs, anchoring of the platform at the top of the interval to be tested and performing the distributed survey using a combination of tractors and linear actuators for every probe displacement. Removing cable movement significantly reduces an important source of error in distributed pressure measurements. These acquisition errors induce interpretation uncertainties like position of contacts and connectivity between flow units. These have profound impacts in exploration and appraisal decisions and field development plans. This concept platform would enable reducing the time spent on pressure surveys if similar accuracy to current standard practices is acceptable. Because the remaining source of error is mostly due to gauge accuracy, results show that fewer stations are necessary to replicate standard wireline results. Where accuracy is important, as with distributed pressure measurements to quantify reserves using gradient intersection to define fluid contacts or determine compositional gradients, the proposed approach is shown to significantly reduce gradient error using the same number of stations. We use synthetic data sets built from previous work to show the impact of the error reduction in the position of the fluid contact. IWITs currently used in cased hole employ active anchoring to perform intervention tasks. The controlled downhole force available for these operations goes up to 80,000 lbf while the anchoring force could be up to 150,000 lbf. In the proposed concept platform, this pulling force could be instrumental where there is high risk of differential sticking. By anchoring the upper part of the platform in overlying impermeable intervals, the probe could be lowered into the permeable interval to conduct the pressure survey without exposing the full length of the platform to the pressure differential forces for significant risk mitigation. The high pulling capacity of the anchoring module can be used to apply up/down force on the probe in case of differential sticking without applying high tensions to the wireline cable. The proposed architecture for the concept platform innovatively combines several operational concepts used today
{"title":"Let's Disrupt the Wireline Pressure Testing Practices, Shall We?","authors":"G. Garcia, H. duMond, V. Mishra, L. Chen, Ron Hayden, C. Babin","doi":"10.2118/195016-MS","DOIUrl":"https://doi.org/10.2118/195016-MS","url":null,"abstract":"\u0000 A concept platform integrating the precise movement of a linear or azimuthal actuator, such as in instrumented wireline intervention tools (IWIT), with fast pressure measurement is presented. This device is intended to accurately move a measurement probe or sampling assembly either in the longitudinal or azimuthal direction in the wellbore to significantly improve data quality and operational efficiency.\u0000 Precise movement control enables acquiring data at exact intervals to eliminate errors induced by cable stretching, overpulls, or variable cable creep. Monte Carlo simulations of this concept using current IWIT capabilities suggest significant reduction of the pressure gradient uncertainty over common wireline protocols. The operational procedure includes correlation using standard wireline gamma ray logs, anchoring of the platform at the top of the interval to be tested and performing the distributed survey using a combination of tractors and linear actuators for every probe displacement. Removing cable movement significantly reduces an important source of error in distributed pressure measurements. These acquisition errors induce interpretation uncertainties like position of contacts and connectivity between flow units. These have profound impacts in exploration and appraisal decisions and field development plans.\u0000 This concept platform would enable reducing the time spent on pressure surveys if similar accuracy to current standard practices is acceptable. Because the remaining source of error is mostly due to gauge accuracy, results show that fewer stations are necessary to replicate standard wireline results. Where accuracy is important, as with distributed pressure measurements to quantify reserves using gradient intersection to define fluid contacts or determine compositional gradients, the proposed approach is shown to significantly reduce gradient error using the same number of stations. We use synthetic data sets built from previous work to show the impact of the error reduction in the position of the fluid contact.\u0000 IWITs currently used in cased hole employ active anchoring to perform intervention tasks. The controlled downhole force available for these operations goes up to 80,000 lbf while the anchoring force could be up to 150,000 lbf. In the proposed concept platform, this pulling force could be instrumental where there is high risk of differential sticking. By anchoring the upper part of the platform in overlying impermeable intervals, the probe could be lowered into the permeable interval to conduct the pressure survey without exposing the full length of the platform to the pressure differential forces for significant risk mitigation. The high pulling capacity of the anchoring module can be used to apply up/down force on the probe in case of differential sticking without applying high tensions to the wireline cable.\u0000 The proposed architecture for the concept platform innovatively combines several operational concepts used today","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79856444","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}
Polymer gel treatment is a successful technology for conformance improvement. Achieving effective deep conformance control in high-temperature reservoirs requires improving the performance of gel in these environments and a deep understanding of gel-conformance control mechanisms inside reservoir rocks. In this work, a laboratory study was conducted to evaluate a polyacrylamide/chromium gel system for a carbonate reservoir at high-temperature and high-salinity (HTHS) conditions. Displacement experiments combined with nuclear magnetic resonance (NMR) measurements were performed to investigate the mechanisms of conformance treatment as well as demonstrate the potential of oil production improvement by a gelling system. Coreflooding tests were performed on carbonate core samples with different configurations of high-permeability channels. Both gel treatment and polymer flooding experiments were conducted to quantify and differentiate between fluid-diversion and viscous effects on oil production improvement due to the treatment. Detailed spatial fluid variations inside the core samples before and after gel treatment were closely monitored using low-field NMR techniques. Both coreflooding experiments and NMR measurements clearly showed that significant oil production improvement was achieved by gel treatment. The bypassed oil during waterflooding was effectively mobilized. Gel treatment is more efficient in oil production improvement for more heterogeneous core samples. The comparison study of gel treatment and polymer flooding helps gain insight into the mechanisms of oil displacement. Results show that the blockage or fluid-diversion effect plays a more significant role in oil production improvement after gel treatment. The viscous effect of gelant flow helps mobilize oil in the matrix region. The oil production improvement by gel treatment is mainly attributed to the fluid-diversion effect, especially for the treatment in high-permeable configuration. Moreover, results of the study demonstrate the potential of the studied gel system for carbonate reservoirs at high temperature. NMR techniques add additional valuable information to conventional displacement tests to identify the dominant mechanisms of oil mobilization.
{"title":"A Closer Look on Viscosity and Divergence Effects of Gel Treatments in Fractured Systems","authors":"A. Alshehri, Jinxun Wang, H. Kwak, A. Alsofi","doi":"10.2118/194964-MS","DOIUrl":"https://doi.org/10.2118/194964-MS","url":null,"abstract":"\u0000 Polymer gel treatment is a successful technology for conformance improvement. Achieving effective deep conformance control in high-temperature reservoirs requires improving the performance of gel in these environments and a deep understanding of gel-conformance control mechanisms inside reservoir rocks.\u0000 In this work, a laboratory study was conducted to evaluate a polyacrylamide/chromium gel system for a carbonate reservoir at high-temperature and high-salinity (HTHS) conditions. Displacement experiments combined with nuclear magnetic resonance (NMR) measurements were performed to investigate the mechanisms of conformance treatment as well as demonstrate the potential of oil production improvement by a gelling system. Coreflooding tests were performed on carbonate core samples with different configurations of high-permeability channels. Both gel treatment and polymer flooding experiments were conducted to quantify and differentiate between fluid-diversion and viscous effects on oil production improvement due to the treatment. Detailed spatial fluid variations inside the core samples before and after gel treatment were closely monitored using low-field NMR techniques.\u0000 Both coreflooding experiments and NMR measurements clearly showed that significant oil production improvement was achieved by gel treatment. The bypassed oil during waterflooding was effectively mobilized. Gel treatment is more efficient in oil production improvement for more heterogeneous core samples. The comparison study of gel treatment and polymer flooding helps gain insight into the mechanisms of oil displacement.\u0000 Results show that the blockage or fluid-diversion effect plays a more significant role in oil production improvement after gel treatment. The viscous effect of gelant flow helps mobilize oil in the matrix region. The oil production improvement by gel treatment is mainly attributed to the fluid-diversion effect, especially for the treatment in high-permeable configuration. Moreover, results of the study demonstrate the potential of the studied gel system for carbonate reservoirs at high temperature. NMR techniques add additional valuable information to conventional displacement tests to identify the dominant mechanisms of oil mobilization.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82698447","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}
G. Craddock, Federico Ríos, Thomas Earl Burky, J. Rodgers, M. Serra, T. Khairy
Side-mounted gun strings present a unique challenge for predictive perforation modeling tools because of their asymmetric geometry. To fully capture the dynamic response of the side-mounted system and more accurately predict the response of any gun system in general, it is important to fully capture the three-dimensional (3D) effects of model geometry and detonation-induced loading. This work details the modeling approach developed for a side-mounted gun system that enables the full geometry to be simulated so that accurate predictions of stresses and displacements could be made; these predictions are necessary for evaluating the damage potential to sensitive tools in the string, It is important to allow operation designers to optimize gun spacing and provide string flexibility to help ensure it can withstand downhole conditions without affecting performance. The simulation methodology was calibrated against previous test measurements, where loads and accelerations were captured during surface testing of a gun string. A detailed model was developed for the planned operation, and simulations were performed to predict the dynamic response of the wellbore fluid and tool string. Multiple damage sensitivities were identified for particular tools, and model results were extracted to evaluate 1) pressure dynamic loading on the tool, 2) displacement levels where movement is expected, and 3) dynamic loading of the tool. These results were provided to the developers of the sensitive tool to help assess potential damage risks. For each case, predictions were compared to previous test results and operation experience to develop a risk evaluation for the planned operation. Further, results were used to make adjustments to the operation to help optimize performance; comparison plots are presented for the different configurations evaluated. This overall process provided confidence to the operators that the operation would be performed successfully with no damage to the sensitive tool.
{"title":"Dynamic Response of Side-Mounted Guns and Assessment of the Potential Damage Risk to Sensitive Tools","authors":"G. Craddock, Federico Ríos, Thomas Earl Burky, J. Rodgers, M. Serra, T. Khairy","doi":"10.2118/195006-MS","DOIUrl":"https://doi.org/10.2118/195006-MS","url":null,"abstract":"\u0000 Side-mounted gun strings present a unique challenge for predictive perforation modeling tools because of their asymmetric geometry. To fully capture the dynamic response of the side-mounted system and more accurately predict the response of any gun system in general, it is important to fully capture the three-dimensional (3D) effects of model geometry and detonation-induced loading.\u0000 This work details the modeling approach developed for a side-mounted gun system that enables the full geometry to be simulated so that accurate predictions of stresses and displacements could be made; these predictions are necessary for evaluating the damage potential to sensitive tools in the string, It is important to allow operation designers to optimize gun spacing and provide string flexibility to help ensure it can withstand downhole conditions without affecting performance.\u0000 The simulation methodology was calibrated against previous test measurements, where loads and accelerations were captured during surface testing of a gun string. A detailed model was developed for the planned operation, and simulations were performed to predict the dynamic response of the wellbore fluid and tool string. Multiple damage sensitivities were identified for particular tools, and model results were extracted to evaluate 1) pressure dynamic loading on the tool, 2) displacement levels where movement is expected, and 3) dynamic loading of the tool. These results were provided to the developers of the sensitive tool to help assess potential damage risks.\u0000 For each case, predictions were compared to previous test results and operation experience to develop a risk evaluation for the planned operation. Further, results were used to make adjustments to the operation to help optimize performance; comparison plots are presented for the different configurations evaluated. This overall process provided confidence to the operators that the operation would be performed successfully with no damage to the sensitive tool.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82720495","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}
Global energy demand has driven the petroleum industry to develop hydrocarbon resources from extremely harsh formations which contain ultra-high pressure and temperature (HPHT) reservoirs. Ultra-high density drilling fluids are critical to successful drilling and completion practices in all of these wells. In this paper, potential weighting materials were systematically evaluated and screened to accomplish an ultra-high density oil-based drilling fluid system (19.62 to 22.12lb/gal) aimed to utilize in ultra HPHT conditions (>30000psi and >410°F). Several potential high-density weighting materials were evaluated in the laboratory conditions. Basic properties (pure density, particle size/distribution, surface area etc.) were evaluated and compared. Special treatments were conducted to optimize the properties of weighting materials. HPHT filtration tests under static and dynamic conditions were conducted at higher than 410°F and 300 psi. Real cores with an average porosity of 19% and an average permeability of 50 mD were used in the filtration tests. Rheological properties, sag tendency, the volume of filtrate, and the filtrate cake characterization of oil-based drilling fluids were measured before and after heating at 410°F for 16 hours. Results revealed that ultra-micro manganese and ilmenite complex after suitable surface treatment could act as an ideal weighting material than ultra-pure barite or other materials, which could fail in rheology and sag controlling measurement with such high temperature and density. The viscosity and filtration analysis confirmed the stability and reliability of this novel ultra-high density oil-based drilling fluid. This study developed a challenged drilling fluid system under critical testing states, as well as established a systematical laboratory evaluation and screening procedure of weighting materials for ultra-deep wells and contributed recommendations on how to utilize it in the fields.
{"title":"Laboratory Evaluation of Weighting Materials for Ultra-High Density Oil-Based Drilling Fluids in Ultra-HPHT Wellbore Applications","authors":"Qinghui Li, Jinzhi Zhu, Shaoxuan Li, Zhang Shaojun, Nasr-El-Din Hisham, Ren Lingling, Jiaxue Li, M. Al-Mujalhem","doi":"10.2118/194842-MS","DOIUrl":"https://doi.org/10.2118/194842-MS","url":null,"abstract":"\u0000 Global energy demand has driven the petroleum industry to develop hydrocarbon resources from extremely harsh formations which contain ultra-high pressure and temperature (HPHT) reservoirs. Ultra-high density drilling fluids are critical to successful drilling and completion practices in all of these wells. In this paper, potential weighting materials were systematically evaluated and screened to accomplish an ultra-high density oil-based drilling fluid system (19.62 to 22.12lb/gal) aimed to utilize in ultra HPHT conditions (>30000psi and >410°F).\u0000 Several potential high-density weighting materials were evaluated in the laboratory conditions. Basic properties (pure density, particle size/distribution, surface area etc.) were evaluated and compared. Special treatments were conducted to optimize the properties of weighting materials. HPHT filtration tests under static and dynamic conditions were conducted at higher than 410°F and 300 psi. Real cores with an average porosity of 19% and an average permeability of 50 mD were used in the filtration tests. Rheological properties, sag tendency, the volume of filtrate, and the filtrate cake characterization of oil-based drilling fluids were measured before and after heating at 410°F for 16 hours.\u0000 Results revealed that ultra-micro manganese and ilmenite complex after suitable surface treatment could act as an ideal weighting material than ultra-pure barite or other materials, which could fail in rheology and sag controlling measurement with such high temperature and density. The viscosity and filtration analysis confirmed the stability and reliability of this novel ultra-high density oil-based drilling fluid.\u0000 This study developed a challenged drilling fluid system under critical testing states, as well as established a systematical laboratory evaluation and screening procedure of weighting materials for ultra-deep wells and contributed recommendations on how to utilize it in the fields.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79570736","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}
Arctic is widely considering as the last world biggest storehouse of natural resources. But its unique nature should always remain the main concern for all the energy projects development in this area. To achieve this development of the Arctic should go along with innovative technologies development. The ambition of this paper is to provide assessment of main Arctic projects on international energy markets development.
{"title":"Development of the Arctic and its Impact on International Energy Market","authors":"I. Akimova","doi":"10.2118/195070-MS","DOIUrl":"https://doi.org/10.2118/195070-MS","url":null,"abstract":"\u0000 Arctic is widely considering as the last world biggest storehouse of natural resources. But its unique nature should always remain the main concern for all the energy projects development in this area. To achieve this development of the Arctic should go along with innovative technologies development. The ambition of this paper is to provide assessment of main Arctic projects on international energy markets development.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79106505","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}
The key factor for characterizing unconventional shale reservoirs is the total organic carbon (TOC). TOC is estimated conventionally by analysis cores samples which requires extensive lab work, thus it is time-consuming and costly. Several empirical models are suggested to estimate the TOC indirectly using conventional well logs. These models assume the TOC and well logs are linearly related, this assumption significantly reduces the TOC estimation accuracy. In this work, the design parameters of the artificial neural network (ANN) were optimized using self-adaptive differential evolution (SaDE) method to effectively predict the TOC from the conventional well log data. A new correlation for TOC calculation was developed, which is based on the optimized SaDE-ANN model. 460 data points of different well logs from Barnett formation were used to learn and validate the optimized SaDE-ANN model. The predictability of the SaDE-ANN correlation was compared with the available correlations for predicting the TOC using 29 data point from Duvernay formation. The TOC was estimated using the optimized SaDE-ANN model with an average absolute percentage error (AAPE) and correlation coefficient (R) of 6% and 0.98, respectively. The SaDE-ANN correlation developed for TOC prediction outperformed the recent models suggested by Wang et al. (2016) and Mahmoud et al. (2017). The new empirical equation reduced the AAPE in predicting the TOC by 67% compared to Mahmoud et al. (2017) model in Duvernay formation.
总有机碳(TOC)是表征非常规页岩储层的关键因素。TOC通常是通过分析岩心样品来估计的，这需要大量的实验室工作，因此既耗时又昂贵。提出了几种利用常规测井资料间接估算TOC的经验模型。这些模型假设TOC和测井曲线是线性相关的，这种假设大大降低了TOC估计的精度。采用自适应差分进化(SaDE)方法对人工神经网络(ANN)的设计参数进行优化，从常规测井资料中有效预测TOC。在优化的SaDE-ANN模型的基础上，建立了一种新的TOC计算关联。利用Barnett地层的460个不同测井数据点来学习和验证优化后的SaDE-ANN模型。将SaDE-ANN相关性的可预测性与利用Duvernay地层29个数据点预测TOC的可用相关性进行了比较。利用优化后的SaDE-ANN模型估计TOC，平均绝对百分比误差(AAPE)和相关系数(R)分别为6%和0.98。用于TOC预测的SaDE-ANN相关性优于Wang等人(2016)和Mahmoud等人(2017)提出的最新模型。与Mahmoud et al.(2017)的Duvernay地层模型相比，新的经验方程将预测TOC的AAPE降低了67%。
{"title":"New Artificial Neural Network Model for Predicting the TOC from Well Logs","authors":"A. Sultan","doi":"10.2118/194716-MS","DOIUrl":"https://doi.org/10.2118/194716-MS","url":null,"abstract":"\u0000 The key factor for characterizing unconventional shale reservoirs is the total organic carbon (TOC). TOC is estimated conventionally by analysis cores samples which requires extensive lab work, thus it is time-consuming and costly. Several empirical models are suggested to estimate the TOC indirectly using conventional well logs. These models assume the TOC and well logs are linearly related, this assumption significantly reduces the TOC estimation accuracy.\u0000 In this work, the design parameters of the artificial neural network (ANN) were optimized using self-adaptive differential evolution (SaDE) method to effectively predict the TOC from the conventional well log data. A new correlation for TOC calculation was developed, which is based on the optimized SaDE-ANN model. 460 data points of different well logs from Barnett formation were used to learn and validate the optimized SaDE-ANN model. The predictability of the SaDE-ANN correlation was compared with the available correlations for predicting the TOC using 29 data point from Duvernay formation.\u0000 The TOC was estimated using the optimized SaDE-ANN model with an average absolute percentage error (AAPE) and correlation coefficient (R) of 6% and 0.98, respectively. The SaDE-ANN correlation developed for TOC prediction outperformed the recent models suggested by Wang et al. (2016) and Mahmoud et al. (2017). The new empirical equation reduced the AAPE in predicting the TOC by 67% compared to Mahmoud et al. (2017) model in Duvernay formation.","PeriodicalId":10908,"journal":{"name":"Day 2 Tue, March 19, 2019","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74337685","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}
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