M. Cimic, M. Sadivnyk, O. Doroshenko, S. Kovalchuk
Volumetric gas reservoirs are driven by the compressibility of gas and a formation rock, and the ultimate recovery factor is independent of the production rate but depends on the reservoir pressure. The gas saturation in the volumetric reservoir is constant, and the gas volume is reduced causing pressure drop in the reservoir. Due to this reason, it is crucial to minimize the abandonment pressure to the lowest possible level. Concerning Dnipro-Donetsk Basin (DDB) gas reservoirs, it is widespread to recover sometimes more than 90% of the OGIP. Often, OGIP was estimated not considering lower permeability gas layers due to inaccurate logging equipment used in the past, causing that such layers were not included in the total netpay. This is one of the reasons for OGIP overestimation and higher recovery factors. On many P/Z graphs, we observe that at certain drawdown, lower permeability reservoirs kick in lifting up P/Z plot curve. Abandonment pressure is a major factor in determining recovery efficiency. Permeability and skin are usually the most critical factors in determining the magnitude of the abandonment pressure. Reservoirs with low permeability will have higher abandonment pressures than reservoirs with high permeability. A specific minimum flow rate must be sustained to keep the well unloading process, and a higher permeability will permit this minimum flow rate at lower reservoir pressure. Abandonment pressure will depend on wellhead pressure, friction and hydrostatic pressures in the system, pressure drop in reservoir, and pressure drop due to skin. This last factor is often neglected, which sometimes leads to a significant reduction of the recovery factor. It is common practice that skin factor and pressure drop due to the skin are solved with well stimulation. Also, well stimulation has its limits concerning the level of reservoir pressure. It is very common that the stimulation effect of low reservoir pressure well is negligible or even negative. This is caused by the minimum required drawdown to flow back a stimulating aqueous fluid out of the reservoir. The required minimum drawdown is caused by the Phase Trapping Coefficient (PTC), which drives reservoir stimulation fluid cleaning behavior. For water drive gas reservoirs, Cole (1969) suggests that the recovery is substantially less than recovery from bounded gas reservoirs. As a rule of thumb, recovery from a water-drive reservoir will be approximately 50 to 75% of the initial gas in place. The structural location of producing wells and the degree of water coning are essential considerations in determining ultimate recovery. In the cases studied in this paper, we consider gas and rock expansion reservoir energy, if abandonment pressure needs to be coupled with a water drive, then it is recommended to use a numerical, not analytical approach.
{"title":"Influence of Abandonment Pressure on Recoverable Reserves, Special Application to the Depleted Dnipro-Donetsk Basin Reservoirs","authors":"M. Cimic, M. Sadivnyk, O. Doroshenko, S. Kovalchuk","doi":"10.2118/208523-ms","DOIUrl":"https://doi.org/10.2118/208523-ms","url":null,"abstract":"\u0000 Volumetric gas reservoirs are driven by the compressibility of gas and a formation rock, and the ultimate recovery factor is independent of the production rate but depends on the reservoir pressure. The gas saturation in the volumetric reservoir is constant, and the gas volume is reduced causing pressure drop in the reservoir. Due to this reason, it is crucial to minimize the abandonment pressure to the lowest possible level. Concerning Dnipro-Donetsk Basin (DDB) gas reservoirs, it is widespread to recover sometimes more than 90% of the OGIP. Often, OGIP was estimated not considering lower permeability gas layers due to inaccurate logging equipment used in the past, causing that such layers were not included in the total netpay. This is one of the reasons for OGIP overestimation and higher recovery factors. On many P/Z graphs, we observe that at certain drawdown, lower permeability reservoirs kick in lifting up P/Z plot curve.\u0000 Abandonment pressure is a major factor in determining recovery efficiency. Permeability and skin are usually the most critical factors in determining the magnitude of the abandonment pressure. Reservoirs with low permeability will have higher abandonment pressures than reservoirs with high permeability. A specific minimum flow rate must be sustained to keep the well unloading process, and a higher permeability will permit this minimum flow rate at lower reservoir pressure.\u0000 Abandonment pressure will depend on wellhead pressure, friction and hydrostatic pressures in the system, pressure drop in reservoir, and pressure drop due to skin. This last factor is often neglected, which sometimes leads to a significant reduction of the recovery factor. It is common practice that skin factor and pressure drop due to the skin are solved with well stimulation. Also, well stimulation has its limits concerning the level of reservoir pressure. It is very common that the stimulation effect of low reservoir pressure well is negligible or even negative. This is caused by the minimum required drawdown to flow back a stimulating aqueous fluid out of the reservoir. The required minimum drawdown is caused by the Phase Trapping Coefficient (PTC), which drives reservoir stimulation fluid cleaning behavior.\u0000 For water drive gas reservoirs, Cole (1969) suggests that the recovery is substantially less than recovery from bounded gas reservoirs. As a rule of thumb, recovery from a water-drive reservoir will be approximately 50 to 75% of the initial gas in place. The structural location of producing wells and the degree of water coning are essential considerations in determining ultimate recovery. In the cases studied in this paper, we consider gas and rock expansion reservoir energy, if abandonment pressure needs to be coupled with a water drive, then it is recommended to use a numerical, not analytical approach.","PeriodicalId":11215,"journal":{"name":"Day 2 Wed, November 24, 2021","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83857651","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}
This paper presents a holistic approach to modern oilfield and well surveillance through the inclusion of state-of-the-art edge computing applications in combination with a novel type of data transmission technology and algorithms developed in-house for automatic condition monitoring of SRP systems. The objective is to enable the responsible specialist staff to focus on the most important decisions regarding oilfield management, rather than wasting time with data collection and preparation. An own operated data communication system, based on LPWAN-technology transfers the dyno-cards, generated by an electric load cell, into the in-house developed production assistance software platform. Suitable programmed AI-algorithms enable automatic condition detection of the incoming dyno cards, including conversion and analysis of the corresponding subsurface dynamograms. A smart alarming system informs about occurring failure conditions and specifies whether an incident of rod rupture, pump-off condition, gas lock or paraffin precipitation occurred in the well. A surface mounted measuring device delivers liquid level and bottomhole pressure information automatically into the software. Based on these diverse data, the operations team plans the subsequent activities. The holistic application approach is illustrated using the case study of an SPR-operated well in an Austrian brownfield.
{"title":"The SMART SRP Well – Application of Edge Analytics for Automated Well Performance Control and Condition Monitoring in a Mature Brownfield Environment – A Case Study from Austria","authors":"Christian Windisch","doi":"10.2118/208521-ms","DOIUrl":"https://doi.org/10.2118/208521-ms","url":null,"abstract":"\u0000 This paper presents a holistic approach to modern oilfield and well surveillance through the inclusion of state-of-the-art edge computing applications in combination with a novel type of data transmission technology and algorithms developed in-house for automatic condition monitoring of SRP systems. The objective is to enable the responsible specialist staff to focus on the most important decisions regarding oilfield management, rather than wasting time with data collection and preparation.\u0000 An own operated data communication system, based on LPWAN-technology transfers the dyno-cards, generated by an electric load cell, into the in-house developed production assistance software platform. Suitable programmed AI-algorithms enable automatic condition detection of the incoming dyno cards, including conversion and analysis of the corresponding subsurface dynamograms. A smart alarming system informs about occurring failure conditions and specifies whether an incident of rod rupture, pump-off condition, gas lock or paraffin precipitation occurred in the well. A surface mounted measuring device delivers liquid level and bottomhole pressure information automatically into the software. Based on these diverse data, the operations team plans the subsequent activities.\u0000 The holistic application approach is illustrated using the case study of an SPR-operated well in an Austrian brownfield.","PeriodicalId":11215,"journal":{"name":"Day 2 Wed, November 24, 2021","volume":"274 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83514608","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}
Kirill Victorovich Mironenko, Oleg Leonidovich Voytekhin, V. V. Marchenko
Currently, the vast majority of the oil fields of the Republic of Belarus are at the final stage of development. In this connection, in order to expand the resource base, Belarusian oil companies are assigned with the task of searching, exploring and developing hard-to-recover reserves. In recent years, a number of geological works have been carried out to search and study the sedimentary cover rocks of the Belarusian part of the Pripyat Trough, the results of these works were the discovery of promising deposits of the Petrikov Horizon of the Upper Devonian. These deposits are represented by dense fractured carbonate rocks with ultra-low permeability (less than 0.01 mD) and low effective porosity (up to 10%). The most promising technology for the development of such reservoirs is the drilling of horizontal wells and the subsequent implementation of Multistage hydraulic fracturing. This article presents the experience of developing ultra-low-permeability reservoirs in the Republic of Belarus in the period 2014-2021, briefly describes the main technologies used, the evolution of technological solutions for effective involvement in the active development of hard-to-recover reserves.
{"title":"A Case Study of High-Rate Multistage Hydraulic Fracturing in Petrikov Horizon of the Pripyat Trough","authors":"Kirill Victorovich Mironenko, Oleg Leonidovich Voytekhin, V. V. Marchenko","doi":"10.2118/208516-ms","DOIUrl":"https://doi.org/10.2118/208516-ms","url":null,"abstract":"\u0000 Currently, the vast majority of the oil fields of the Republic of Belarus are at the final stage of development. In this connection, in order to expand the resource base, Belarusian oil companies are assigned with the task of searching, exploring and developing hard-to-recover reserves. In recent years, a number of geological works have been carried out to search and study the sedimentary cover rocks of the Belarusian part of the Pripyat Trough, the results of these works were the discovery of promising deposits of the Petrikov Horizon of the Upper Devonian.\u0000 These deposits are represented by dense fractured carbonate rocks with ultra-low permeability (less than 0.01 mD) and low effective porosity (up to 10%). The most promising technology for the development of such reservoirs is the drilling of horizontal wells and the subsequent implementation of Multistage hydraulic fracturing.\u0000 This article presents the experience of developing ultra-low-permeability reservoirs in the Republic of Belarus in the period 2014-2021, briefly describes the main technologies used, the evolution of technological solutions for effective involvement in the active development of hard-to-recover reserves.","PeriodicalId":11215,"journal":{"name":"Day 2 Wed, November 24, 2021","volume":"159 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76794639","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}
V. Privalov, Valentyn Loktyev, D. Misch, R. Sachsenhofer, I. Karpenko, O. Panova
Since 1950, when the megascale Shebelinka deposit was found in the north-eastern portion of the Dnieper-Donets basin (DDB) this district has been served as a heartland of the hydrocarbon extraction in Ukraine. Right now, this area is again facing a new wave of commercial interest. Most conventional hydrocarbon plays here contain natural gas and liquid gas accumulated in numerous clastic and fractured horizons throughout Carboniferous to Lower Permian successions. The numerical basin modelling in the Donbas segment indicated that organic-rich sediments are thermally mature in the deep levels of the basin. Our interpretation of the structural patterns within the study area suggests that the kinematic development of the fracture sets is consistent with the model of development of subsidiary structures within the dextral strike-slip zone. Nearly all gas and gas condensate fields in the eastern part of the DDB may be classified as naturally fractured reservoirs in fault-breached anticlinal traps associated with releasing jogs in strike-slip assemblages. Gaseous hydrocarbons generated in deep "gas window" compartments have escaped here via several fracture corridors forming "sweet spots " sites. The main objective of this contribution is to get an insight into the style and structural trends of formation structural traps of hydrocarbons which in concert with basin modeling technologies will ensure proper technical decisions for the efficient exploration and production of gas reservoirs. This research summarizes new insights into gas deposits formation in the eastern part of DDB based on a synthetic approach ascertaining a vital connection of basin modeling results with the spatial distribution of kinematically induced releasing jogs which facilitating magnified fluid-and-gas conductivity.
{"title":"Conditions of the Formation Gas Deposits in the Epart of the Dnieper-Donets Basin: Integration of Basin Modeling Data with Consequences of Strike-Slip Faulting Effects","authors":"V. Privalov, Valentyn Loktyev, D. Misch, R. Sachsenhofer, I. Karpenko, O. Panova","doi":"10.2118/208543-ms","DOIUrl":"https://doi.org/10.2118/208543-ms","url":null,"abstract":"\u0000 Since 1950, when the megascale Shebelinka deposit was found in the north-eastern portion of the Dnieper-Donets basin (DDB) this district has been served as a heartland of the hydrocarbon extraction in Ukraine. Right now, this area is again facing a new wave of commercial interest. Most conventional hydrocarbon plays here contain natural gas and liquid gas accumulated in numerous clastic and fractured horizons throughout Carboniferous to Lower Permian successions. The numerical basin modelling in the Donbas segment indicated that organic-rich sediments are thermally mature in the deep levels of the basin.\u0000 Our interpretation of the structural patterns within the study area suggests that the kinematic development of the fracture sets is consistent with the model of development of subsidiary structures within the dextral strike-slip zone. Nearly all gas and gas condensate fields in the eastern part of the DDB may be classified as naturally fractured reservoirs in fault-breached anticlinal traps associated with releasing jogs in strike-slip assemblages. Gaseous hydrocarbons generated in deep \"gas window\" compartments have escaped here via several fracture corridors forming \"sweet spots \" sites.\u0000 The main objective of this contribution is to get an insight into the style and structural trends of formation structural traps of hydrocarbons which in concert with basin modeling technologies will ensure proper technical decisions for the efficient exploration and production of gas reservoirs.\u0000 This research summarizes new insights into gas deposits formation in the eastern part of DDB based on a synthetic approach ascertaining a vital connection of basin modeling results with the spatial distribution of kinematically induced releasing jogs which facilitating magnified fluid-and-gas conductivity.","PeriodicalId":11215,"journal":{"name":"Day 2 Wed, November 24, 2021","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81784670","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}
Aidyn Kartamyssov, Beibit Bissakayev, Bolat Zhumabayev, Raziya Shektebayeva, M. Durekovic, B. Akbayev, Y. Kaipov
The objective of this paper is to demonstrate multiple application of multi-energy gamma ray venture type multiphase flowmeter (MPFM) trial campaign in Karachaganak gas condensate giant carbonate field, operated by KPO B.V. The results of MPFM that was included into surface well test spread, to verify its performance, was compared against portable test separator and plant production testing facilities (control separator, flowmeters) and manual sampling results. MPFM from other vendors historically failed to deliver accurate production measurement mainly due to complexity of reservoir fluid in Karachaganak field. To ensure the MPFM considers this complexity, PVT samples were taken to provide laboratory data for PVT model of the MPFM to ensure sufficient quality of PVT data and compare against PVT model inside MPFM. First application of MPFM was during clean-up of the well prior handover well to production. Using MPFM helped to improve the quality during data acquisition. This information was critical for the well to be accepted by processing facility it is hooked-up to and to define optimal operating regime. Validation of BS&W, GOR and rates in unstable (foaming, carry over) and transient phase of production using MPFM has shown practical advantages. Another application was for water sampling loops to measure water cut and production rates. KPO has had challenges with inaccurate water cut measurement due to the limitations of existing test separators. A recent approach of performing fluid sampling (sampling loop) at the well head proved to be reliable source of measurements. In addition, the MPFM in combination with the test separator has been used to further improve the quality of the measurements of each phase. The third MPFM application had been with high gas-volume-fraction (HGVF) pumps, that helped to produce from low reservoir pressure, low GOR and high water cut wells. The operational range of HGVF pump was limited to maximum 75-80% of gas-volume-fraction (GVF). MPFM measures GVF in real-time to ensure HGVF pump operates in optimum operational range by managing the surface flow conditions. With current limitations of test separators in Karachaganak field and due to complexity of the gas-condensate fluid, the use of MPFM brings additional quality in the measurements (rates, water cut and GOR) which is crucial for field production optimization, reservoir management and short and long term forecasting.
{"title":"Multiple Application of Multi-Energy Gamma Ray Venture Type Multiphase Flowmeter in Giant Karachaganak Gas Condensate Field","authors":"Aidyn Kartamyssov, Beibit Bissakayev, Bolat Zhumabayev, Raziya Shektebayeva, M. Durekovic, B. Akbayev, Y. Kaipov","doi":"10.2118/208522-ms","DOIUrl":"https://doi.org/10.2118/208522-ms","url":null,"abstract":"\u0000 The objective of this paper is to demonstrate multiple application of multi-energy gamma ray venture type multiphase flowmeter (MPFM) trial campaign in Karachaganak gas condensate giant carbonate field, operated by KPO B.V.\u0000 The results of MPFM that was included into surface well test spread, to verify its performance, was compared against portable test separator and plant production testing facilities (control separator, flowmeters) and manual sampling results. MPFM from other vendors historically failed to deliver accurate production measurement mainly due to complexity of reservoir fluid in Karachaganak field. To ensure the MPFM considers this complexity, PVT samples were taken to provide laboratory data for PVT model of the MPFM to ensure sufficient quality of PVT data and compare against PVT model inside MPFM.\u0000 First application of MPFM was during clean-up of the well prior handover well to production. Using MPFM helped to improve the quality during data acquisition. This information was critical for the well to be accepted by processing facility it is hooked-up to and to define optimal operating regime. Validation of BS&W, GOR and rates in unstable (foaming, carry over) and transient phase of production using MPFM has shown practical advantages.\u0000 Another application was for water sampling loops to measure water cut and production rates. KPO has had challenges with inaccurate water cut measurement due to the limitations of existing test separators. A recent approach of performing fluid sampling (sampling loop) at the well head proved to be reliable source of measurements. In addition, the MPFM in combination with the test separator has been used to further improve the quality of the measurements of each phase.\u0000 The third MPFM application had been with high gas-volume-fraction (HGVF) pumps, that helped to produce from low reservoir pressure, low GOR and high water cut wells. The operational range of HGVF pump was limited to maximum 75-80% of gas-volume-fraction (GVF). MPFM measures GVF in real-time to ensure HGVF pump operates in optimum operational range by managing the surface flow conditions.\u0000 With current limitations of test separators in Karachaganak field and due to complexity of the gas-condensate fluid, the use of MPFM brings additional quality in the measurements (rates, water cut and GOR) which is crucial for field production optimization, reservoir management and short and long term forecasting.","PeriodicalId":11215,"journal":{"name":"Day 2 Wed, November 24, 2021","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82779724","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}
D. Lazutkin, O. Bukov, D. Kashapov, A. Drobot, M. Stepanova, Ksenia Mikhailovna Saprykina
New geological structures – displaced blocks of salt diapirs’ overburden – were identified in the axial part of the Dnieper-Donets basin (DDB) beside one of the largest salt domes due to modern high-precision gravity and magnetic surveys and their joint 3D inversion with seismic and well log data. Superposition of gravity lineaments and wells penetrating Middle and Lower Carboniferous below Permian and Upper Carboniferous sediments in proximity to salt allowed to propose halokinetic model salt overburden displacement, assuming Upper Carboniferous reactivation. Analogy with rafts and carapaces of the Gulf of Mexico is considered in terms of magnitude of salt-induced deformations. Density of Carboniferous rocks within the displaced flaps evidence a high probability of hydrocarbon saturation. Possible traps include uplifted parts of the overturned flaps, abutting Upper Carboniferous reservoirs, and underlying Carboniferous sequence. Play elements are analyzed using analogues from the Dnieper-Donets basin and the Gulf of Mexico. Hydrocarbon reserves of the overturned flaps within the study area are estimated to exceed Q50 (Р50) = 150 million cubic meters of oil equivalent.
{"title":"An Integrated Approach to Well Logging: The Case of the Bazhenov Formation","authors":"D. Lazutkin, O. Bukov, D. Kashapov, A. Drobot, M. Stepanova, Ksenia Mikhailovna Saprykina","doi":"10.2118/208545-ms","DOIUrl":"https://doi.org/10.2118/208545-ms","url":null,"abstract":"\u0000 New geological structures – displaced blocks of salt diapirs’ overburden – were identified in the axial part of the Dnieper-Donets basin (DDB) beside one of the largest salt domes due to modern high-precision gravity and magnetic surveys and their joint 3D inversion with seismic and well log data.\u0000 Superposition of gravity lineaments and wells penetrating Middle and Lower Carboniferous below Permian and Upper Carboniferous sediments in proximity to salt allowed to propose halokinetic model salt overburden displacement, assuming Upper Carboniferous reactivation.\u0000 Analogy with rafts and carapaces of the Gulf of Mexico is considered in terms of magnitude of salt-induced deformations.\u0000 Density of Carboniferous rocks within the displaced flaps evidence a high probability of hydrocarbon saturation. Possible traps include uplifted parts of the overturned flaps, abutting Upper Carboniferous reservoirs, and underlying Carboniferous sequence. Play elements are analyzed using analogues from the Dnieper-Donets basin and the Gulf of Mexico.\u0000 Hydrocarbon reserves of the overturned flaps within the study area are estimated to exceed Q50 (Р50) = 150 million cubic meters of oil equivalent.","PeriodicalId":11215,"journal":{"name":"Day 2 Wed, November 24, 2021","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88149077","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}
High-speed rotordynamic pump operation for downhole or surface production is required and also beneficial to handle very high gas volume fraction (GVF) flows. Operating speeds of these pumps can be in excess of twice those of conventional pumps. This study presents results showing a high-speed helico-axial pump (HAP) can operate satisfactorily at intake GVFs up to 98%. The findings increase capabilities of field engineers and operators to boost and maximize production from high gas-content wells. The HAP tested had a housing outer diameter of 4.00-inch and operated at a rotational speed of 6000 revolutions per minutes (RPM). Air and water were the test fluids with the water volume flow rate held constant while the air volume flow rate was varied. The liquid and gas volume flow rates varied from 63 to 143 barrels per day (BPD), and 549 to 3238 BPD, respectively. Intake pressures varied from 14 to 76 psig, with average inlet temperature of 18°C. The corresponding discharge pressures and temperatures were recorded for each test point and observed for stable pump operation. The results showed that the HAP had stable operation during the tests for intake GVF range from 84% to 98%. Pump discharge pressures for this range of high intake GVF varied from 21 to 89 psig. The corresponding differential pressures across the HAP all had positive magnitudes indicating that at such high-speeds, the HAP was still able to add energy to the fluid even with the high gas content at intake. Analysis at fixed intake pressure with varying GVFs showed that the discharge-to-intake pressure ratio decreased with increasing intake GVF. For instance, at 33psig intake pressure, increasing the intake GVF from 84% to 94% decreased the discharge-to-intake pressure ratio from about 1.27 to 1.20, respectively. It was also observed that tightening the clearance between the impeller and diffuser of the HAP increased the discharge pressure compared to when the clearance was loose. Furthermore, ensuring the upstream flow is properly conditioned also improved the stable operation of the HAP. Overall and in conclusion, running a HAP at high speeds in addition to optimizing certain features of the HAP can result in stable pump operation and enhanced pressure boosting in high-GVF flows. This study mainly highlights the importance of operating HAPs at high speeds of up to 6000 RPM. Tightening clearances between rotordynamic components as well as tailored inlet flow conditioning are also additional features that enhance pressure boosting. This architecture opens up opportunities for field operators, and engineering personnel to maximize hydrocarbon production from their very high-gas content field assets, thereby increasing the economic bottomline for the stakeholders.
{"title":"Physical Testing of a High-Speed Helico-Axial Pump for High-GVF Operation","authors":"C. E. Ejim, J. Xiao, Wee Sun Lee, Wilson Zabala","doi":"10.2118/208552-ms","DOIUrl":"https://doi.org/10.2118/208552-ms","url":null,"abstract":"\u0000 High-speed rotordynamic pump operation for downhole or surface production is required and also beneficial to handle very high gas volume fraction (GVF) flows. Operating speeds of these pumps can be in excess of twice those of conventional pumps. This study presents results showing a high-speed helico-axial pump (HAP) can operate satisfactorily at intake GVFs up to 98%. The findings increase capabilities of field engineers and operators to boost and maximize production from high gas-content wells.\u0000 The HAP tested had a housing outer diameter of 4.00-inch and operated at a rotational speed of 6000 revolutions per minutes (RPM). Air and water were the test fluids with the water volume flow rate held constant while the air volume flow rate was varied. The liquid and gas volume flow rates varied from 63 to 143 barrels per day (BPD), and 549 to 3238 BPD, respectively. Intake pressures varied from 14 to 76 psig, with average inlet temperature of 18°C. The corresponding discharge pressures and temperatures were recorded for each test point and observed for stable pump operation.\u0000 The results showed that the HAP had stable operation during the tests for intake GVF range from 84% to 98%. Pump discharge pressures for this range of high intake GVF varied from 21 to 89 psig. The corresponding differential pressures across the HAP all had positive magnitudes indicating that at such high-speeds, the HAP was still able to add energy to the fluid even with the high gas content at intake. Analysis at fixed intake pressure with varying GVFs showed that the discharge-to-intake pressure ratio decreased with increasing intake GVF. For instance, at 33psig intake pressure, increasing the intake GVF from 84% to 94% decreased the discharge-to-intake pressure ratio from about 1.27 to 1.20, respectively. It was also observed that tightening the clearance between the impeller and diffuser of the HAP increased the discharge pressure compared to when the clearance was loose. Furthermore, ensuring the upstream flow is properly conditioned also improved the stable operation of the HAP. Overall and in conclusion, running a HAP at high speeds in addition to optimizing certain features of the HAP can result in stable pump operation and enhanced pressure boosting in high-GVF flows.\u0000 This study mainly highlights the importance of operating HAPs at high speeds of up to 6000 RPM. Tightening clearances between rotordynamic components as well as tailored inlet flow conditioning are also additional features that enhance pressure boosting. This architecture opens up opportunities for field operators, and engineering personnel to maximize hydrocarbon production from their very high-gas content field assets, thereby increasing the economic bottomline for the stakeholders.","PeriodicalId":11215,"journal":{"name":"Day 2 Wed, November 24, 2021","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80871483","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}
Y. Akashev, S. Ahmad, C. Cavalleri, Yulia Ignatochkina, Yevgenii Solodkiy
Field A is located in the center of the Dnieper-Donets basin (DDB), producing gas from clastic reservoirs from several deep horizons in the Upper Visean sediments. The case study highlights the application of advanced pulsed neutron logging technologies and high-resolution data processing to unlock the sedimentary layers’ characteristics and the gas potential behind the casing. Multiple rock measurements are simultaneously recorded for continuous lithology identification, porosity quantification, and differentiating gas-filled porosity from low porosity formations. Dedicated log data acquisition and processing techniques enable investigating the effect of thin laminations on reservoir quality and producibility. The use of advanced pulsed neutron logging and interpretation method reduces the operational risks while securing critical reservoir parameters. A pulsed neutron spectroscopy tool provided a rich dataset including a self-compensated sigma and neutron porosity logs, fast neutron cross section (FNXS) together with capture and inelastic elemental spectroscopy. The logs interpretation was performed integrating FNXS and very high-resolution neutron porosity with mineral dry weight fractions and matrix properties from elemental spectroscopy processing. The comparison between the pulsed neutron measurements with standard open hole logs highlights the critical role of advanced fit-to-purpose logging techniques to accurately describe the underlying complexity of the formation and obtain improved net reservoir and net pay thicknesses in laminated and heterogeneous sequences. The logging objectives were successfully met, and additional valuable information related to the reservoir were determined in an efficient manner. The study also shows the critical value of FNXS as confident gas measurement. The FNXS measures the ability of the formation interacting with fast neutrons which are highly dependent on atomic density and not dominated by particular isotopes such as traditional sigma and porosity measurements. It is highly sensitive to gas-filled porosity, but it is independent of hydrogen index, acting like a cased-hole density measurement. Moreover, it demonstrates the importance of accurate knowledge of the mineralogy and matrix as well as the ability to measure at very high resolution to unravel the highly layered nature of the formation and its implication on completion and production strategy. Pulsed neutron logging has evolved over a half century, but the intrinsic physical measurements remain unchanged. With the advent and introduction of the new FNXS measurement and a high-quality spectroscopy elemental concentration, a higher quality measurement and interpretation can be obtained from standalone pulsed neutron logging. The advanced technology and log data analysis interpretation module can be considered as an effective and comprehensive methodology for robust formation evaluation in similar and complex setting.
{"title":"Unlocking Potential in Thinly Laminated Reservoirs Through Cased Hole Pulsed Neutron Logging","authors":"Y. Akashev, S. Ahmad, C. Cavalleri, Yulia Ignatochkina, Yevgenii Solodkiy","doi":"10.2118/208557-ms","DOIUrl":"https://doi.org/10.2118/208557-ms","url":null,"abstract":"\u0000 Field A is located in the center of the Dnieper-Donets basin (DDB), producing gas from clastic reservoirs from several deep horizons in the Upper Visean sediments. The case study highlights the application of advanced pulsed neutron logging technologies and high-resolution data processing to unlock the sedimentary layers’ characteristics and the gas potential behind the casing. Multiple rock measurements are simultaneously recorded for continuous lithology identification, porosity quantification, and differentiating gas-filled porosity from low porosity formations. Dedicated log data acquisition and processing techniques enable investigating the effect of thin laminations on reservoir quality and producibility.\u0000 The use of advanced pulsed neutron logging and interpretation method reduces the operational risks while securing critical reservoir parameters. A pulsed neutron spectroscopy tool provided a rich dataset including a self-compensated sigma and neutron porosity logs, fast neutron cross section (FNXS) together with capture and inelastic elemental spectroscopy. The logs interpretation was performed integrating FNXS and very high-resolution neutron porosity with mineral dry weight fractions and matrix properties from elemental spectroscopy processing. The comparison between the pulsed neutron measurements with standard open hole logs highlights the critical role of advanced fit-to-purpose logging techniques to accurately describe the underlying complexity of the formation and obtain improved net reservoir and net pay thicknesses in laminated and heterogeneous sequences.\u0000 The logging objectives were successfully met, and additional valuable information related to the reservoir were determined in an efficient manner. The study also shows the critical value of FNXS as confident gas measurement.\u0000 The FNXS measures the ability of the formation interacting with fast neutrons which are highly dependent on atomic density and not dominated by particular isotopes such as traditional sigma and porosity measurements. It is highly sensitive to gas-filled porosity, but it is independent of hydrogen index, acting like a cased-hole density measurement. Moreover, it demonstrates the importance of accurate knowledge of the mineralogy and matrix as well as the ability to measure at very high resolution to unravel the highly layered nature of the formation and its implication on completion and production strategy.\u0000 Pulsed neutron logging has evolved over a half century, but the intrinsic physical measurements remain unchanged. With the advent and introduction of the new FNXS measurement and a high-quality spectroscopy elemental concentration, a higher quality measurement and interpretation can be obtained from standalone pulsed neutron logging. The advanced technology and log data analysis interpretation module can be considered as an effective and comprehensive methodology for robust formation evaluation in similar and complex setting.","PeriodicalId":11215,"journal":{"name":"Day 2 Wed, November 24, 2021","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84912213","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}
Wells that are already drilled and producing are the most viable sources of future earnings for all oilfield operating companies. Keeping these wells producing economically at optimal rates throughout their lifetimes is top priority. With time, some oilfield operating companies face with production related problems, such us water breakthrough. Production logging is well known technique for locating source of water breakthrough in oil and gas producers. In near-vertical, or slightly deviated wells, producing at high rates, traditional production logging tool string can deliver reliable results. On the other side, in deviated wells, producing at small rates, advanced production logging tool is required, due to presence of fluid segregation and recirculation within borehole. Our experience shows that wisely selected logging technique, depending on downhole logging environment, allows to locate source of water production with confidence for planning water shut-off remedial operations. In wells completed with standalone sand screens water shut-off operation might be complicated as often rig is required for pulling out of hole tubing with sand screens. Another method is to perform chemical water shut-off treatment that might be expensive in some cases. Alternative method is to confirm compact sand accumulation in the annulus and set through tubing bridge plug inside sand screens in wells that producing water from bottommost layers. Plug is deployed in wells without pulling out of hole tubing, as it can pass through restrictions, making this rigless intervention fifty times cheaper compared to intervention with rig. Field examples, presented in this paper, describe fit-for-purpose logging approach for locating source of water production accurately and executing unique rigless water shut-off operations in cased wells completed with standalone sand screens to increase hydrocarbons production in cost-effective way. After remedial operations we observed significant decline in water production and increase in oil rates in all wells that were intervened.
{"title":"Locating Source of Water Production and Performing Cost-Effective Rigless Remedial Operations in Deviated Wells Completed with Standalone Sand Screens","authors":"A. Timonin, Eldar Mollaniyazov","doi":"10.2118/208547-ms","DOIUrl":"https://doi.org/10.2118/208547-ms","url":null,"abstract":"Wells that are already drilled and producing are the most viable sources of future earnings for all oilfield operating companies. Keeping these wells producing economically at optimal rates throughout their lifetimes is top priority. With time, some oilfield operating companies face with production related problems, such us water breakthrough.\u0000 Production logging is well known technique for locating source of water breakthrough in oil and gas producers. In near-vertical, or slightly deviated wells, producing at high rates, traditional production logging tool string can deliver reliable results. On the other side, in deviated wells, producing at small rates, advanced production logging tool is required, due to presence of fluid segregation and recirculation within borehole. Our experience shows that wisely selected logging technique, depending on downhole logging environment, allows to locate source of water production with confidence for planning water shut-off remedial operations.\u0000 In wells completed with standalone sand screens water shut-off operation might be complicated as often rig is required for pulling out of hole tubing with sand screens. Another method is to perform chemical water shut-off treatment that might be expensive in some cases. Alternative method is to confirm compact sand accumulation in the annulus and set through tubing bridge plug inside sand screens in wells that producing water from bottommost layers. Plug is deployed in wells without pulling out of hole tubing, as it can pass through restrictions, making this rigless intervention fifty times cheaper compared to intervention with rig.\u0000 Field examples, presented in this paper, describe fit-for-purpose logging approach for locating source of water production accurately and executing unique rigless water shut-off operations in cased wells completed with standalone sand screens to increase hydrocarbons production in cost-effective way. After remedial operations we observed significant decline in water production and increase in oil rates in all wells that were intervened.","PeriodicalId":11215,"journal":{"name":"Day 2 Wed, November 24, 2021","volume":"48 7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82807669","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}
A methodology has been developed that, in conditions of limited geological and production data, ensures the integration of petrophysical, geological, and hydrodynamic models as components of a permanent 3D model, establishing physical relationships between parameters that describe the entire system. In the proposed method, the modelling is based on the results of the interpretation of continuous shale volume and porosity curves. Based on the analysis of core data, the multi-vector physical correlations with other parameters are made. To distinguish the reservoirs and non-reservoirs, the cut-off values of shale volume are defined; to exclude tight reservoirs with no filtration, the cut-off values of porosity are set. Using the Winland R35 method the radius of the pore throat is computed, allowing dividing the reservoirs into classes. For each class of reservoirs, the permeability vs porosity dependence is determined, and the Wright-Woody-Johnson method allows deriving equations for the bound water content. A system of configured workflows has been developed and allows automating re-modelling and simplifying its history matching. This technique was successfully applied to several 3D models of gas condensate fields, which, with a significant drilling level on the areas and a long development history, are characterized by limited geological and production data. Workflows System together with the proposed approach allowed simplifying the history matching process by splitting it into several stages. At each stage, depending on the type of input data, various parameters were matched (production, reservoir and wellhead pressures, etc.). Due to cross-functional correlation of all components, the model has significantly reduced the uncertainty parameters and allowed a detailed history matching of the development history for the entire well stock. The results obtained were tested by several geological and technological measures, including drilling new wells, and showed high convergence with the forecast indicators. The proposed approach to modelling and history matching in conditions of limited geological and production data allows: – ensuring integration and correlation of petrophysical, geological, and hydrodynamic models as components of a permanent 3D model; – automating and simplifying the modelling, history matching, and updating a model; – improving the quality of parameters’ matching results.
{"title":"A Novel Integrated Approach to 3D Modeling and History Matching of Gas Condensate Fields with Paucity of Geological and Production Data","authors":"D. Grytsai, Petro Shtefura, Vadym Dodukh","doi":"10.2118/208518-ms","DOIUrl":"https://doi.org/10.2118/208518-ms","url":null,"abstract":"\u0000 A methodology has been developed that, in conditions of limited geological and production data, ensures the integration of petrophysical, geological, and hydrodynamic models as components of a permanent 3D model, establishing physical relationships between parameters that describe the entire system.\u0000 In the proposed method, the modelling is based on the results of the interpretation of continuous shale volume and porosity curves. Based on the analysis of core data, the multi-vector physical correlations with other parameters are made. To distinguish the reservoirs and non-reservoirs, the cut-off values of shale volume are defined; to exclude tight reservoirs with no filtration, the cut-off values of porosity are set. Using the Winland R35 method the radius of the pore throat is computed, allowing dividing the reservoirs into classes. For each class of reservoirs, the permeability vs porosity dependence is determined, and the Wright-Woody-Johnson method allows deriving equations for the bound water content. A system of configured workflows has been developed and allows automating re-modelling and simplifying its history matching.\u0000 This technique was successfully applied to several 3D models of gas condensate fields, which, with a significant drilling level on the areas and a long development history, are characterized by limited geological and production data. Workflows System together with the proposed approach allowed simplifying the history matching process by splitting it into several stages. At each stage, depending on the type of input data, various parameters were matched (production, reservoir and wellhead pressures, etc.). Due to cross-functional correlation of all components, the model has significantly reduced the uncertainty parameters and allowed a detailed history matching of the development history for the entire well stock. The results obtained were tested by several geological and technological measures, including drilling new wells, and showed high convergence with the forecast indicators.\u0000 The proposed approach to modelling and history matching in conditions of limited geological and production data allows:\u0000 – ensuring integration and correlation of petrophysical, geological, and hydrodynamic models as components of a permanent 3D model; – automating and simplifying the modelling, history matching, and updating a model; – improving the quality of parameters’ matching results.","PeriodicalId":11215,"journal":{"name":"Day 2 Wed, November 24, 2021","volume":"154 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85376703","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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