Day 2 Tue, October 27, 2020最新文献

{"title":"Application of Pressure Interference Test Without Stopping the Well Stock to Regulate the Process of Field Development of the NOVATEK Group of Companies","authors":"Kristina Dvinskikh, F. Zavalin, A. Naimushin, A. Abdrakhimov","doi":"10.2118/201892-ms","DOIUrl":"https://doi.org/10.2118/201892-ms","url":null,"abstract":"\u0000 The main objectives of field development are to maintain high profitability, as well as to achieve the highest coefficient of oil recovery (COR). One of the ways to ensure a high COR for oil fields is creation of a reservoir pressure decrease system (RPD). So, for example, when create a system of RPD, the COR can reach 0.5 d. q., and without RPD - only 0.1-0.2 d. q In the case of designing the development of oil fields with a complex geological structure (the presence of a gas cap, block structure of the Deposit, a large number of faults), the complexity of the task of choosing the optimal development system increases significantly.\u0000 In Russia and in the world, there are a considerable number of oil fields that have been developed for a long time on the depletion mode, which has led to the formation of a considerable volume of the free gas phase. Such deposits often pass into the category of problematic and are characterized by low current values of the coefficient of oil recovery (COR), as well as the lack of reliable technological solutions for their effective development. Examples include the Talinsky area of the Krasnoleninsky field, the oil pool in the Jurassic sediments of the Novogodnee Deposit, and others. When the pressure increases further, for example, by pumping water, modeling the development of such deposits requires the use of non-equilibrium hydrodynamic models.\u0000 Application of the results of the pressure interference test (PIT) allows us to obtain valuable information about the connectivity of inter-well intervals, a quantitative assessment of the conductivity of reservoir faults, and, consequently, reduce risks when planning field development, increase the efficiency of ongoing geological and technical measures and their profitability. Conducting of PIT on a working stock, in comparison with classical methods, allows you to minimize the loss of production during research. Proper planning of field development with the involvement of PIT results, in particular-the introduction of the RPD system, allows to increase the COR and profitability of the development system as a whole.\u0000 The paper shows the results of the pressure interference test studies for a tectonically complicated structure of an oil and gas condensate field. Based on the results of the research, the efficiency of the existing RPD system was evaluated and decisions were made to transfer production wells to injection, taking into account the assessment of the risks of water breaks through conducting faults. In addition, the results of the pressure interference test were combined with the results of tracer studies. The convergence of research results by both methods is shown.","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133401879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multivariate Optimization of the Development Systems for Low–Permeability Reservoirs of Oil Fields of the Achimov Formation","authors":"A. Fedorov, I. R. Dilmuhametov, A. Povalyaev, M. Antonov, A. Sergeychev","doi":"10.2118/201811-ms","DOIUrl":"https://doi.org/10.2118/201811-ms","url":null,"abstract":"\u0000 The aim of this work is to develop an approach to multivariate optimization of development systems for tight oil reservoirs of the Achimov formation, where large volume of drilling of RN-Yuganskneftegaz LLC are currently concentrated on. The approach described in the paper is an integral part of the corporate module \"Decision Support System for drilling out new sections of tight oil reservoirs\", which allows making quick design decisions for new drilling sites of target objects.\u0000 The main factors that reduce the development efficiency of such objects, in particular with the use of water flooding methods, are the low piezoconductivity and high heterogeneity of a reservoir that leads to relatively high rates of decline in fluid production and, in particular, to long response productivity time for production wells to injection.\u0000 In this paper, we consider a multi-criteria assessment of the effectiveness of various well placement systems in various conditions that characterize the geological features of tight oil reservoirs and low-connected reservoirs. A specific example is considered - tight oil heterogeneous reservoir of the northern part of Priobskoye field, for which oil production is calculated by numerical hydrodynamic modeling methods.\u0000 As a result of development and testing of the approach:\u0000 Main geological and technological parameters are estimated that affect development indicators and empirical dependencies derivation (of the development indicators) on the geological features of the selected clusters of Priobskoye field target objects; A method being proposed for description of a various geological features of the reservoirs of Achimov formation target objects by using synthetic stochastic 3D geological models; A physically-meaningful approach is proposed for adaption of well dynamics that reveal tight oil reservoirs of target objects using synthetic 3D geological and hydrodynamic models. Based on the actual data of development (well operation), formation parameters are determined for each cluster (section) of the target objects of Priobskoye field, which differ in geological features and development indicators; Prediction multivariate numerical calculations were carried out for various well placement systems under various geological conditions (≈ 3 million calculations). A database of calculated development indicators has been formed for each variation of the well placement system; Different options are presented for visualization of calculation results in the form of dimensional templates of optimal development systems for tight oil reservoirs; Various options for sensitivity analysis visualization for the effectiveness assessment are presented of various well placement systems to changes in geological, technological and scenario conditions.","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132204552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Approbation of Reserves Geochemical Control Technology in Example of AC10 and AC12 Group Formation in Priobskoye Field of LLC Gazpromneft-Khantos","authors":"N. Morozov, M. Bikkulov, R. Uchuev, M. Martynov, R. Islamov, A. Shurunov, D. Kalacheva","doi":"10.2118/201903-ms","DOIUrl":"https://doi.org/10.2118/201903-ms","url":null,"abstract":"\u0000 In order to improve tools for monitoring the reserves recovery and localization at the Gazprom Neft fields, as part of the technological strategy, a technology for geochemical control of reserves recovery has been developed.\u0000 The use of geochemistry methods in identifying the targeted flow of fluids from a reservoir is based on the difference in fluids’ composition and properties from reservoir to reservoir. According to laboratory experiments, the accuracy of the geochemical predictions of miscibility based on a multiple linear regression model varies from 1 to 8% for oils and condensates, from 6% to 18% for gases, and from 15% to 34% for reservoir water (provided there is no pressure maintenance system in a reservoir).\u0000 The technology was tested at Priobskoye field of Gazpromneft-Khantos LLC, which jointly operates Zones AS10 and AS12. The pilot program included 5 wells with pre-installed Y-tool assemblies. The advantage of this system is the ability to conduct tests in a well producing in a stable state with induced pressure drawdown. Simultaneous geophysical studies and wellhead sampling for geochemical studies allowed us to confirm matching of the results of dividing the inflow under the conditions of a well draining two or more target zones.\u0000 The technology for geochemical control of reserves recovery will allow a breakthrough in the study of wellhead fluid samples in the near future, and such information will increase the success rate and information content of field geophysical studies by an order of magnitude. The advantage of the described technology is 100% coverage of the production well stock and the ability to predict miscibility for all types of fluids (oil, gas, and produced water).","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129981382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive Substantiation of a Horizontal Wellbore Inflow Model in a Fractured Carbonate Reservoir","authors":"N. Morozovskiy, R. Kanevskaya, A. A. Pimenov, V. Kolesov, Lubov Yuryevna Zasukhina","doi":"10.2118/201893-ms","DOIUrl":"https://doi.org/10.2118/201893-ms","url":null,"abstract":"\u0000 The practice of developing fractured reservoirs suggests that the description of the well-reservoir system often does not correspond to the behavior predicted by classical filtration theories for fractured systems (Warren-Root and others). This fact is very clear when analyzing the operation of horizontal wells, in which significant heterogeneity of the distribution of the inflow profile along the well.\u0000 Thus, the reservoir cannot represents like a homogeneous system, and forecasting the operation of wells requires the use of new methods for describing reservoir systems.\u0000 In the course of analyzing the operation of wells in one of the oil and gas condensate fields in Eastern Siberia, a deviation from the forecast parameters obtained by the traditional method is noted. In this regard, a detailed analysis of previously performed logs and well tests in order to refine the model of inflow to horizontal wellbores is detailed.\u0000 At the initial stage, was performed a comprehensive analysis of the operation of the reference wells. These wells have the most extensive set of studies (PTA, PLT, advanced complex of well logging, micro imagers). The analysis revised the approach to the description of the inflow model. Further, the results scaled to the rest of the existing fund of producing horizontal wells.\u0000 In the course of the analysis, our team revealed a significant deviation of the actual filtration model from earlier ideas about the operation of this reservoir.\u0000 According to the results of combining various research methods in the reference wells, we revealed the predominant effect of local fractured intervals on the operation of the entire horizontal well. In this regard, the approach to the description of well productivity and the forecast of their operation revised. In addition, authors identified a significant influence of the degassing of reservoir fluid on well productivity, and the range of the target bottomhole pressure was determined.\u0000 The acquired knowledge about the filtration model of reference wells was scaled for the entire exploration horizontal wells, which made it possible to identify patterns in the formation of productivity in the entire field.\u0000 An approach has been developed to describe the operation of horizontal wells under the conditions of opening an unevenly fractured carbonate reservoir, based on a combination of PLT, well test and open-hole well logging. Additionally, authors studied various machine-learning algorithms to adapt the results of the interpretation of open-hole logging to PLT data.\u0000 To predict the launch parameters and dynamics of horizontal well flow rates, the rejection of the filtration model in a homogeneous isotropic reservoir in favor of the inflow model to local fractured intervals is justified.\u0000 This will make it possible to clarify the current levels of production in wells, optimize well operation modes, and make recommendations for conducting geological and technical measures.","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126079817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Results of Pilot and Industrial Application of Thermal-Gas-Chemical Well Treatment with Binary Mixtures and Development of Mathematical Models for Reservoir Processes in Source Oil Rock","authors":"Alexander Nikolaevich Lishcuk, M. Kravchenko, N. Shesternina, N. N. Dieva, A. A. Nafikov, M. Khisametdinov, A. V. Kataev","doi":"10.2118/201812-ms","DOIUrl":"https://doi.org/10.2118/201812-ms","url":null,"abstract":"\u0000 The purpose of this paper is to generalize the experience of applying the thermo-gas-chemical treatment methods (TGCT) using binary mixtures based on ammonium nitrate to enhance the inflow at oil fields. More than a decade of industrial tests of binary mixtures injection into mature fields’ marginal wells showed a multiple long-term increase in oil inflow. The positive experience of TGCT application to Tatarstan oil fields strongly suggests the perspective of its application to the layers with high content of organic substance in rock matrix including Bazhenov formation reservoirs for those technologies have been only battle-tested. The development of mathematical methods for describing the TGCT process considering the multiphase and multi-component nature of the process, chemical reactions and transformation of the reservoir structure allow to respond to the features of each field at the macro scale, to identify micro-scale features and changes in the reservoir matrix structure, using a percolation approach, and allowed to assess the current state of the bottom-hole zone adequately and conduct pilot tests on specific wells in strict accordance with the established technological regulations and control of hydrodynamic parameters.","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126133171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fruit Extracts as Natural, Green, Non-Toxic Corrosion Inhibitors","authors":"J. H. Ng, Tariq Almubarak, H. Nasr-El-Din","doi":"10.2118/201330-ms","DOIUrl":"https://doi.org/10.2118/201330-ms","url":null,"abstract":"\u0000 Corrosion inhibitors currently used in the oil and gas industry are associated with environmental concerns and severe health risks. Recent advancements in corrosion inhibition technology had successfully tackled environmental concerns, but still faces issues with toxicity and performance at high temperatures. This work aims to develop environmentally friendly and non-toxic corrosion inhibitors that can overcome these limitations. Extracts of 14 common fruits were tested as sources of potential corrosion inhibitors.\u0000 In order to determine the inhibition effectiveness of the different fruits, N-80 coupons were exposed to 15 wt.% HCl solutions at temperatures between 77-250 °F with 0.2-2 wt.% of dried ground fruit for 6 hours. In addition, a control solution containing no corrosion inhibitor was used to establish a corrosion rate for a base case. Upon identifying high performing dried ground fruits, extracts of these fruits were subsequently tested to save cost by minimizing quantity needed while achieving acceptable performance.\u0000 At a concentration of 2 wt.%, fruits 1 and 2 were found to perform the best, exhibiting more than 98% corrosion inhibition efficiency at 77°F. Fruits 11 and 12 were observed to perform the worst, going so far as to enhance corrosion on the coupons. At 150°F, the corrosion rate of fruit extract 1 was 0.00436 lb/ft2, while that of fruit extract 2 was 0.0277 lb/ft2. At 200°F, the addition of a corrosion inhibitor intensifier resulted in a corrosion rate of 0.00130 lb/ft2 for fruit extract 1 and 0.0173 lb/ft2 for fruit extract 2. At 250°F, a second corrosion inhibitor intensifier was used. The resulting corrosion rate was 0.0320 lb/ft2 for fruit extract 1 and 0.00963 lb/ft2 for fruit extract 2. These results show that a naturally occurring, green, non-toxic corrosion inhibitor can be developed from these fruits and can comfortably pass the industry requirement of achieving corrosion rates below 0.05 lb/ft2 for low carbon steel tubulars.\u0000 Corrosion during acid treatments causes destruction to the tubulars and downhole equipment. Consequently, this leads to an increase in expenditure to maintain well production rates and well integrity. Therefore, corrosion inhibitors must be included in any acid treatment formulation. The results in this work share two new naturally occurring, green, non-toxic, high-temperature stable corrosion inhibitors that can be developed from fruits and can successfully protect the tubular during acid treatments.","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125573099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Completion Effects on Diagnosing Multistage Fracture Treatments with Distributed Temperature Sensing","authors":"Shohei Sakaida, D. Zhu, A. Hill","doi":"10.2118/201604-ms","DOIUrl":"https://doi.org/10.2118/201604-ms","url":null,"abstract":"\u0000 Distributed temperature sensing (DTS) is a valuable tool to diagnose multistage hydraulic fracture treatments. When a stage interval is shut-in, the clusters which take more fluid during pumping warm up more slowly. Therefore, the fluid volume injected into each cluster can be quantitatively interpreted by numerical inversion of the warm-back temperature behavior. This general concept assumes that the different warm-back behavior is controlled by only the injected fluid volume, however, recent observations of DTS data indicate that completion configurations significantly influence the warm-back behavior.\u0000 This paper investigates the completion effects on the DTS interpretation. In ideal conditions, when a stage is fractured, the upstream stage intervals should show an almost uniform temperature that is close to the injected fluid temperature. This is due to the high fluid velocity of injected fluid in the wellbore, and the upstream intervals have not been perforated (non-communicating intervals). Thus, the only heat transfer is heat conduction between the wellbore fluid and the surrounding reservoir. But the field DTS data show considerably irregular variations in temperature along the upstream stage intervals. These variations are caused by the completion effects. The non-uniform temperature profile is caused by different heat transfer behavior induced by completion hardware along the production casing string such as joints, clamps, and blast protectors, and by the sensing cable location in the cement, as well as the cement quality. Since the heat transfer behavior impacts the warm-back behavior as well as the temperature profile, the completion effects need to be considered in DTS interpretation.\u0000 A method of DTS interpretation considering the completion effects to diagnose multistage fracture treatments was developed. Since the heat transfer between a wellbore and a reservoir depends on the overall heat transfer coefficient describing heat conduction through the completion in a forward model, this parameter needs to be tuned along the entire wellbore. To calibrate the completion effect, the temperature inversion is conducted using the temperature measured at a stage interval that is upstream of a stage interval currently being treated. Since the interpreted stage interval is not perforated at that time, the thermal behavior at the non-communicating interval is governed by only the heat conduction through the completion environment. Once the effective values of the overall heat transfer coefficient are estimated along the interpreted stage interval, they can be assumed to be constant physical parameters. Then, the fluid volume distribution is interpreted by using the effective overall heat transfer coefficient profile along each interval.\u0000 The interpretation method developed in this study was demonstrated using field data, and it was concluded that the new DTS interpretation method provides more accurate diagnosis of fracture treatments.","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130721319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational Fluid Dynamics Model to Improve Sucker Rod Pump Operating Mode","authors":"Shreyas V. Jalikop, B. Scheichl, S. Eder, S. Hönig","doi":"10.2118/201285-ms","DOIUrl":"https://doi.org/10.2118/201285-ms","url":null,"abstract":"\u0000 Artificial lift pumps are widely used in oil production, and among them, sucker rod pumps are conceptually the simplest ones. The reciprocating movement of the plunger triggers the opening and closing of two ball valves, allowing fluid to be pumped to the surface. These valves are subject to long-time erosion and fail as a consequence of this damage mechanism. We demonstrate that understanding the principal damage mechanisms in the necessary depth and breadth requires a thorough examination of the fluid dynamics during the opening and closing action of the ball valves.\u0000 This paper describes the basic ingredients and results of fluid–structure interaction model that simultaneously computes the fluid flow in the traveling valve, the standing valve, and the chamber of sucker rod pumps during a full pump cycle in an efficient and accurate way. The simulations provide necessary insight into the causes of valve damage for realistic standard as well as non-ideal operating conditions of the downhole pump. In particular, simulations based on real pump operating envelopes reveal that the phenomenon of so-called ‘‘mid-cycle valve closure’’ is likely to occur. Such additional closing and opening events of the ball valves multiply situations where the flow conditions are harmful to the individual pump components, leading to efficiency reduction and pump failure.\u0000 The computational-fluid-dynamics model based on the finite-element method serves to accurately describe the opening and closing cycles of the two valves. Most importantly, this approach for the first time allows an analysis of real operating envelopes, derived from actual dynamometer cards. The combination of stroke length, plunger speed, fluid parameters, and velocity at any point inside the pump can thus be investigated at any time during the pump cycle. The flow parameters identified as critical in terms of damaging pump valves or other pump components can set the basis for taking measures to avoid unfavorable operating envelopes in future pump designs.\u0000 Our comprehensive flow model may support field operations throughout the entire well life, ranging from improved downhole pump design to optimized pump operating modes and envelopes as well as in material selections. It is suggested to aid in adapting pump operating conditions to create an ideal interaction between the valves and avoiding the \"mid-cycle valve closure\". Specifically, a so-optimized pump design is expected to drastically extend the operation time before failure of sucker rod pumps. Finally, this type of simulation will speed up new pump or pump component development, and can eliminate or at least reduce the necessity of extensive and costly laboratory testing.","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134294519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using Deconvolution to Estimate Unknown Well Production from Scarce Wellhead Pressure Data","authors":"L. Aluko, J. Cumming, A. Gringarten","doi":"10.2118/201667-ms","DOIUrl":"https://doi.org/10.2118/201667-ms","url":null,"abstract":"Well test analysis requires the knowledge of bottomhole pressure and rates from the well of interest, and from any other well involved in the case of interferences. Sometimes, bottomhole pressures are not available and must be estimated from wellhead pressures, which usually are of lower quality, due to multiphase flow and possible tubing leaks. Converting flowing wellhead pressures to bottomhole pressures can be performed with a number of models, all of which assumes knowledge of the well production rate, which is usually determined with flowmeters or separators at the surface. In some cases, for instance when there is a blow out, production rate information is not available. The question is then how to determine well production rate in the absence of rate measurements when only wellhead pressures are available.In this paper, we use an iterative process based on well test deconvolution (von Schroeter et al. 2001-2004) to estimate unknown well production from wellhead pressure data. The procedure is as follows: (1) we assume a constant unit production rate and apply deconvolution to wellhead pressures: this yields a deconvolved wellhead pressure derivative and corrects the rates to make them compatible with the wellhead pressures; (2) we calibrate the rates with permeability from a trusted source e.g. core measurements or sampling wireline formation test analysis; (3) we use the calibrated deconvolved rates to convert wellhead pressures into bottomhole pressures; (4) we again assume a constant unit production rate and apply deconvolution to calculated bottomhole pressures: this yields a deconvolved bottomhole pressure derivative and corrects the rates to make them compatible with the calculated bottomhole pressures; and (5) we calibrate the calculated rates with trusted permeability information.We have applied the procedure described above to DST data from an oil well for which a complete data set is available, including permeabilities from cores, wellhead pressures, production rates, bottomhole pressures and well test analysis results. For the purpose of this study, we assume that we only know wellhead pressures, and we compare calculated results with measurements, i.e. calculated vs. measured bottomhole pressures, calculated vs. measured rates, and calculated vs. measured cumulative production.We assess the uncertainty in the results by applying a Bayesian approach to deconvolution (Cumming et al. 2020) which accounts for uncertainties in all input parameters, including permeability from different sources, and also uncertainty in deconvolution. In all cases, good to excellent agreement is reached between calculated results and measured data, thus validating the approach and providing confidence in the validity of the results.The procedure described in this paper provides a very good estimate of production rates from only wellhead measurements and permeability estimates: rather than using a welltest to determine reservoir properties knowing the ","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128909347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel Approach to Study the Impact of Asphaltene Properties on Low Salinity Flooding","authors":"S. Hassan, M. Yutkin, S. Kamireddy, C. Radke, T. Patzek","doi":"10.2118/201747-ms","DOIUrl":"https://doi.org/10.2118/201747-ms","url":null,"abstract":"\u0000 Low salinity water flooding (LSW) has gained significant attention, because of its advantages compared with other enhanced oil recovery (EOR) methods. LSW's positive contribution to recovery factor has been demonstrated in the literature at lab and field scales. However, LSW flooding does not always increment oil recovery. It is a specific combination of properties of an asphaltenic crude oil, chemically equilibrated brine, and rock surface that may explain the success or failure of LSW. In this work, we introduce a novel experimental approach to study asphaltene-like chemical interactions with surfaces rock minerals to evaluate the effectiveness of applying LSW.\u0000 When studying the impact of asphaltene properties on incremental recovery, one aims to detach some of the immobile oil, which is semi-irreversibly stuck on rock surface. This is a difficult task, because of varying crude oil composition, as well as asphaltene interfacial and chemical properties. To overcome these issues, we split the problem into several parts. We study how mono- and poly-functional chemical compounds mimic asphaltene interactions with mineral surfaces, like silica and calcium carbonate, which are proxies for sandstones and limestones, respectively. For example, amines, quaternary ammonia or carboxylates represent asphaltene functional groups that are mainly responsible for crude oil base and acid numbers, respectively. Adsorption of polymers and oligomers containing such groups mimics the irreversible asphaltene deposition onto rock surface through formation of chemically active polymerlike structures at the oil-brine interface.\u0000 The silica surface is negatively charged in brines with pH above 2. Silica attracts positively charged ammonia salts, such as cetrimonium chloride (CTAC). However, negatively charged mono-functional carboxylates, i.e. anionic surfactants, like sodium hexanoate (NaHex), hardly adsorb onto silica, even in the presence of a bridging ion, like calcium.\u0000 In contrast to silica, calcium carbonate surface has both positive and negative charges on its surface. We found that CTAC adsorbs onto calcium carbonate in any brine tested. NaHex shows minimal adsorption onto calcium carbonate only in the presence of calcium ions suggesting a contribution of an ion-bridging mechanism.\u0000 Adsorption of all studied mono-functional surfactants is fully reversible and, consequently not representative of asphaltenes. Multifunctional compounds, i.e., polymers, demonstrate irreversible, asphaltene-like, adsorption. We studied adsorption of carbohydrates decorated with individual amines and quaternary ammonia functional groups.\u0000 The carbohydrates with amine functional groups adsorb irreversibly on calcium carbonate and silica in all tested brines with pH up to 10. Therefore, a lower base number (BN) in crude oils indicates a higher potential for LSW.\u0000 Our findings demonstrate the proof of concept that contribution of different functional groups to asphaltene adsorption/d","PeriodicalId":359083,"journal":{"name":"Day 2 Tue, October 27, 2020","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127104004","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}