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Varfolomeev, Mikhail (Kazan Federal University) | Rezaei Koochi, Mojtaba (Kazan Federal University) | Yuan, Chengdong (Kazan Federal University) | Khayrtdinov, Ruslan (CJSC Karaaltyn) | Mustafin, Aidar (Kazan Federal University) | Glukhov, Mikhail (Kazan Federal University) | Kadyrov, Rail (Kazan Federal University) | Sudakov, Vladislav (Kazan Federal University) | Usmanov, Sergey (Kazan Federal University)
Abstract This paper presents the feasibility of the application of ion-modified water for enhanced oil recovery (EOR) in low permeable carbonate reservoir with ultra-high salinity of more than 220000 mg/L. Influence of different ions on wettability alteration, interfacial tension (IFT), scale tendency, recovery factor, and water injectivity was investigated. For choosing the optimized injection-water sequence, different types of water (formation water, distilled water, fresh water, and ion-modified water) were used. First, their effects on wettability alteration by measuring contact angle (oil-water-rock) and IFT were evaluated. Then, core flooding experiments were carried out to investigate how different injection sequence affects the oil recovery and injectivity. Furthermore, the scale tendency of different salts was simulated. The results showed that Mg is the most effective ion. The addition of Mg can fast change the oil-wet (130°) carbonate rock to water-wet (29°). The presence of mono-valent ions has negative effects on the effectiveness of Mg on wettability alteration. Also, the presence of Mg in fresh water and distilled water can reduce oil-water IFT two times lower. Core flooding experiments showed that after fresh water or formation water flooding (until 100% water cut), the sequent diluted formation water (diluted 10 times) yielded incremental oil recovery of about 3-5%, while the Mg modified water obtained incremental oil recovery of about 8-18%. This indicates that Mg modified water has a promising prospect in EOR in carbonate reservoirs. A comprehensive analysis combining contact angle measurements, IFT testing, and core flooding experiments indicates that the high efficiency of Mg modified fresh water for EOR mainly benefits from its strong wettability alteration ability. In addition, it was found that the existence of Mg and SO4 can reduce the tendency of precipitation of salts compared with using only fresh water or diluted formation water. This work proves that ion-modified water by adding Mg to fresh water can be an effective, low cost and environment-friendly EOR method for low-permeability carbonate reservoirs with ultra-high salinity. Simultaneously, this research provides some basic data that can help to enrich the theory for developing low salinity water flooding for EOR.
Pituganova, Anastasia (Kazan Federal University) | Nassan, Taofik (Technical University Bergakademie Freiberg) | Amro, Mohd (Technical University Bergakademie Freiberg) | Minkhanov, Ilgiz (Kazan Federal University) | Varfolomeev, Mikhail (Kazan Federal University) | Bolotov, Alexander (Kazan Federal University)
Abstract Crude oil production from conventional oil reservoirs is declining owing to heavy exploitation to meet the global energy market demand which is growing on a yearly basis. Unconventional oil resources, e.g. extra-heavy oil and bitumen, can compensate for this decline if appropriate enhanced oil recovery (EOR) methods are developed to enable economic flow from these resources. The main objective of this study is to set the best practice for the extra-heavy oil production of the Oykino-Altuninsky uplift of the Romashkinskoye oilfield (Tatarstan Republic, Russia). A series of experimental tests are applied on a real unextracted unconsolidated core sample from Romashkinskoye oilfield where the viscosity of the crude oil is above 600,000 cP at reservoir conditions. Different recovery schemes are tested experimentally and sequentially, namely: water flooding, hot water flooding, steam flooding, and finally in-situ combustion (ISC). Furthermore, the complete experimental run is simulated by a standard nonisothermal simulator and the results are compared to the experiments. On contrary to what was expected hot water at 100°C didn’t achieve any recovery from the sample and steam injection recovered only 11,5% of OOIP. ISC-is also known as fire flooding-attained the best recovery which reached 45% after steam flooding. Complete SARA analysis of the original oil and produced oil by steam and ISC is implemented to understand the mechanisms of each process. Numerical modeling is applied to the corresponding laboratory experiments and the results for water, hot water, and steam flooding were in good agreement with the experimental results while the in-situ combustion simulation showed a better recovery factor than experiments. The laboratory and numerical experiments will improve our understanding of the recovery options of Oykino-Altuninsky uplift of the Romashkinskoye oilfield and help the developers to choose the best production sequence for this oilfield particularly. Moreover, the experiments will provide inputs for the field-size numerical model after running more experiments on unconsolidated and consolidated cores.
Gazprom's oil-focused subsidiary Gazprom Neft has signed a memorandum of understanding with AIQ, a joint venture between the Abu Dhabi National Oil Company (ADNOC) and the UAE-based cloud computing firm Group 42. The firms seek to jointly develop and commercialize digital solutions for the upstream oil and gas industry in Russia and the Middle East. The partners pledged to develop tools for oil and gas exploration and production using cognitive technologies that cross the spectrum of algorithms, robotic process automation, machine learning, natural language processing and generation, and artificial intelligence. This is according to Gazprom Neft's Science & Technology Center, the company's research and development arm. ADNOC and Group 42 created the AIQ joint venture in 2019 to commercialize advanced programming solutions specifically for the oil and gas industry.
Shipovskiy, K. A. (SamaraNIPIneft LLC) | Tsirkova, V. S. (SamaraNIPIneft LLC) | Koval, M. E. (SamaraNIPIneft LLC) | Kozhin, V. N. (SamaraNIPIneft LLC) | Pilipets, E. Yu. (Rosneft Oil Company) | Krepostnov, D. D. (Rosneft Oil Company)
The article discusses the results of the study of the causes of complete and catastrophic lost circulation when drilling exploration and production wells in the reef structures of the Kama-Kinel downfold system. The features of the distribution of zones of mud losses of different intensities in the drowned the Upper Frasnian-Famennian-Tournaisian reef system are analyzed using the example of the Blagodarovsky uplift of the Kuleshovskoye field. It is shown that total and catastrophic lost circulation is mainly confined to the zone of the reef-front apron, which consists of psephitic and weak carbonate rocks. Drilling in a reef-front apron can be accompanied by drilling tool failures with loss of circulation and a significant decrease in the static level of the flush fluid. Partial losses occur, as a rule, in the zone of the carbonate core of the reef, its frontal and rear zones. The absence of losses or insignificant loss of circulation of the drilling fluid is characteristic of the depression (backreef) zone of the organogenic rocks. It was noted that it is important to determine the contours and amplitudes of the drowned reef, the boundaries of its facies zones. This enables to use standard S-shaped profiles when designing wells, bypassing possible intervals of complete and catastrophic lost circulation. At the same time, it allows to make the necessary technical and technological decisions for timely prevention and effective elimination of complications when drilling wells in organogenic massifs. It is shown that a detailed analysis of geological and geophysical information, taking into account the technical and technological data on previously drilled wells, makes it possible to predict zones of possible complications and develop effective measures to prevent complications at the design stage in order to increase the efficiency, reliability and safety of well construction and reduce the cost of drilling works at the fields of Rosneft Oil Company.
When classifying the process of oil dehydration for preliminary assessments of the technological parameters of its treatment at various stages of the design and development of oil fields, it is necessary to take into account regional differences, starting with the geographical and geological location of oil deposits and the conditions of their occurrence, ending with the features of the physicochemical properties of reservoir fluids extracted to the surface. On the example of a number of fields in the Samara region, the dependence of the change in viscosity when changing from reservoir conditions to surface conditions is built, a comparative grouping of oil by viscosity in reservoir and surface conditions is considered, consistent with the classification of oil to assess the parameters of its preparation simultaneously in terms of density and viscosity in surface conditions. A conditional comparison of the classification parameters and the required temperature of the emulsion during oil dehydration to a residual water content of 10 wt% (preliminary dehydration) and 0.5-1 wt% (deep dehydration) was carried out according to various literature sources. It is proposed for the range of Paleozoic production of oil wells in the Volga-Ural oil and gas province, in addition to assessing the generally accepted characteristics of oil density and the content of paraffin in it, to select technological parameters for oil treatment, additionally use the relative indicators, taking into account the unique properties of highly mineralized reservoir waters and the heterogeneous hydrocarbon composition of the oil itself. On the basis of the introduced characteristics, the classification of oil dehydration of a number of fields in the Orenburg, Samara regions and Siberia is considered. A comparative assessment of the quality of wastewater treatment was carried out taking into account two calculation methods based on the properties of the separated phases, taking into account the mentioned characteristics, as well as the oil density and the specific load on the interface of the apparatuses for the combined preparation of oil and water.
Karmushin, S. R. (Gazpromneft STC LLC) | Lezhnev, K. E. (Gazpromneft-Digital Solutions) | Gumerov, R. R. (Gazpromneft STC LLC) | Bazyrov, I. Sh. (Gazpromneft STC LLC) | Gunkin, A. S. (Saint-Petersburg Mining University) | Gvritishvili, T. T. (Gazpromneft-Orenburg LLC)
The purpose of this work is to increase the efficiency of well killing operations for carbonate fractured porous reservoirs with high gas factor, the presence of hydrogen sulphide, and abnormally low formation pressure. Well killing in such conditions is complicated by large losses of technological well killing fluid, which provokes gas kick. In this regard, the calculation of a sufficient well killing fluid volume for operations with a high gas factor in conditions of abnormally low formation pressure is an urgent task, which, along with technological and economic efficiency, should increase the safety of repair work on wells. To solve this problem, a model of filtration of non-Newtonian fluid in the borehole zone was proposed. In the course of this work, the Herschel–Bulkley fluid flow was simulated in a porous medium and in a fracture, and a statistical analysis of field data was performed for comparison with the results obtained by the model. The physical and mathematical model used in this work was built based on continuity equation of the flow and the law of conservation of momentum. As a result, the dependence of the injected well killing fluid volume on the repression applied to the reservoir during the well killing operation was derived. Based on the constructed model, key parameters were obtained which allow us to estimate a fluid volume for successful well killing operation. Then the field data was selected, and statistical analysis was carried out using the parameters identified in the initial model. The retrospective analysis showed good convergence of filed data with the results obtained on the basis of the proposed methodology, which confirmed its validity. As a result, a method for well killing fluid volume estimation was proposed for the conditions of fractured porous reservoirs. It is fair to consider the ratio of the volume of the technological fluid that went into the formation during a successful well killing operation to the repression created during the operation as a criterion for the effectiveness of the use of well killing fluid. This parameter depends on the rheology of the fluid and on the rock filtration-volumetric characteristics. Thus, the proposed analytical model with a simple method for well killing fluid volume estimation allows to predict the parameters for each well killing operation. This methodology can be scaled to other porous and fractured-porous reservoirs.
The overwhelming majority of natural gas fields are at the final stage of development, which, along with other features, is characterized by selective watering of productive deposits and production wells. The difficulty of extracting residual gas reserves under such development conditions is associated with depletion of productive reservoirs, accumulation of fluid at the bottom of wells, corrosion of downhole equipment and the inability to reduce wellhead pressures due to restrictions on the supply and preparation of hydrocarbon products with the existing surface infrastructure. Production wells in conditions of formation water inflow into productive deposits are decommissioned after relatively small gas withdrawals. This is due both to the insufficient implementation of methods for intensifying the removal of fluid from the bottom of the wells, and to the peculiarities of the arrangement of fields, which are usually not designed for the collection and preparation of hydrocarbon products with a high liquid content. In order to remove the gas-liquid mixture from the bottom of the wells, many techniques and inventions have been developed that are widely used in production. The developed technologies are characterized by different efficiency and have a number of technological limitations, mainly due to the peculiarities of the geological structure of hydrocarbon deposits. Considering the above, there is a need for additional research in order to improve the existing and develop new technologies for the operation of water cut wells. Using the special software package, studies were carried out to optimize the operating conditions for a water cut well under conditions of active formation water inflow into gas-saturated horizons. The study was carried out for various depths of gas-lift valves (3500 m; 3000 m; 2500 m; 2000 m; 1500 m; 1000 m) and liquid flow rates (22.5 m/day; 33.75 m/day and 45 m/day). Based on the research results, graphical dependences of gas flow rates and bottomhole pressure on the amount of gas-lift gas were built; the maximum gas flow rate and the required amount of gas-lift gas from the liquid flow rate; maximum gas flow rate versus liquid flow rate at different depths of gas-lift valve installation. Based on the results of statistical processing of the calculated data for each value of the liquid flow rate, the optimal value of the depth of the gas-lift valve was established. According to the results of the studies performed, to ensure the stable operation of high-water cut gas wells, it is effective to locate the gas-lift valve at a distance of 55-58 % from the wellhead of the tubing (2033-2137 m).
Gavrilov, Anton Yurievich (Gazpromneft STC) | Bandaletova, Alexandra Alexandrovna (Gazpromneft STC) | Devleshova, Natalia Alekseevna (Gazpromneft STC) | Galin, Evgeny Vladimirovich (PJSC Gazpromneft) | Pisarev, Mikhail Olegovich (Tyumen State University) | Liss, Dmitry Alexandrovich (Tyumen State University)
Abstract Current production conditions and development of oil fields are complicated by the development of increasingly difficult-to-recover reserves as well as by the consequences of 2020, which include a change in the structure of demand and a collapse of the oil market, the global trend towards low-carb fuel systems and the implementation of the principles of environmental, social and managerial responsibility (ESG). This research paper is focused on diversification of the oil and gas business by extracting lithium from reservoir waters of oil and gas condensate fields. This method allows to increase the profitability of deposits. The paper also carries out a technical and economic assessment of the process of the sorption lithium extraction from the formation waters of oil fields.
Norkina, Anna Vladimirovna (Geonaft) | Karpukhin, Sergey Mihailovich (VolgaGas) | Ruban, Konstantin Urjevich (VolgaGas) | Petrakov, Yuriy Anatoljevich (Geonaft) | Sobolev, Alexey Evgenjevich (Geonaft)
Abstract The design features and the need to use a water-based solution make the task of ensuring trouble-free drilling of vertical wells non-trivial. This work is an example of an interdisciplinary approach to the analysis of the mechanisms of instability of the wellbore. Instability can be caused by a complex of reasons, in this case, standard geomechanical calculations are not enough to solve the problem. Engineering calculations and laboratory chemical studies are integrated into the process of geomechanical modeling. The recommendations developed in all three areas are interdependent and inseparable from each other. To achieve good results, it is necessary to comply with a set of measures at the same time. The key tasks of the project were: determination of drilling density, tripping the pipe conditions, parameters of the drilling fluid rheology, selection of a system for the best inhibition of clay swelling.
Belyakov, Alexander Alexandrovich (Orenburgneft) | Gulyaev, Danila Nikolayevich (Sofoil) | Krichevskiy, Vladimir Markovich (Sofoil) | Nikonorova, Anastasia Nikolaevna (Sofoil) | Iskibaev, Roman Edisonovich (Sofoil)
Abstract The analyzed oi- gas field is based around Orenburg region, located 40 km away from the Buzuluk city, Russia. This multi-layered field has a number of domes. 11 productive layers lie within its cross-section. In total, 21 oil and two gas deposits have been identified at this field. The study layer A4 is confined to the top of the Bashkir layer and has a wide extension. Permeable rocks at this layer include limestone and dolomite, separated by impermeable sublayers. The effective oil-saturated well thicknesses vary between 1.1-38.4 m, and is 11.8 m on average. The caprock of the formation A4 consists of the Vereiskan clay-siltstone sequence.