{"title":"Determination of total organic carbon content using Passey's method in coals of the central Kalahari Karoo Basin, Botswana","authors":"Mamphedi Sylvia Mabitje, Mimonitu Opuwari","doi":"10.1016/j.ptlrs.2022.06.002","DOIUrl":"10.1016/j.ptlrs.2022.06.002","url":null,"abstract":"<div><p>This paper focuses on determining total organic carbon (TOC) from boreholes in the Kalahari Basin, Botswana, using Passey's method. The Kalahari Karoo basin is one of several basins in southern Africa filled with Late Carboniferous to Jurassic sedimentary strata that host Permian age coal seams. Nine exploration boreholes (wells) drilled in the central Kalahari Karoo basin are used to determine the Total Organic Carbon potential. Vitrinite reflectance (<em>R</em><sub>o</sub>), proximate and ultimate analyses were conducted on cored coal intervals. Passey's ΔLogR method applied in this study employs resistivity and porosity logs to identify and quantify potential source rocks. Results of Passey's method compared with laboratory-measured carbon showed that Passey's method effectively identifies coal intervals. In terms of TOC calculations, the method works poorly in coal metamorphosed by dolerite intrusions. The heat affected coal samples had <em>R</em><sub><em>o</em></sub> from 0.77% to 5.53% and increased in maturity from primarily maceral controlled to high volatile bituminous and anthracite coal. Results from proximate analysis showed compositional changes in the coal were controlled by proximity to sill intrusion, with a decrease in Fixed Carbon and an increase in ash yield in the contact metamorphism zone (2–12 m from sill). For the unaltered coal that has undergone burial maturation displaying <em>R</em><sub>o</sub> of 0.44%–0.65%, the method works well. In unintruded boreholes, correlations between Carbon and calculated TOC indicate strong relationships. Passey's ΔLogR method proved to be a suitable method of estimating TOC on coal that has undergone burial maturation. This study has demonstrated that TOC calculated from the sonic log is more reliable in coal not affected by contact metamorphism than TOC calculated from the density log.</p></div>","PeriodicalId":19756,"journal":{"name":"Petroleum Research","volume":"8 2","pages":"Pages 192-204"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45476568","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}
Dmitriy A. Martyushev , Inna N. Ponomareva , Evgenii V. Filippov
{"title":"Studying the direction of hydraulic fracture in carbonate reservoirs: Using machine learning to determine reservoir pressure","authors":"Dmitriy A. Martyushev , Inna N. Ponomareva , Evgenii V. Filippov","doi":"10.1016/j.ptlrs.2022.06.003","DOIUrl":"https://doi.org/10.1016/j.ptlrs.2022.06.003","url":null,"abstract":"<div><p>Hydraulic fracturing (HF) is an effective way to intensify oil production, which is currently widely used in various conditions, including complex carbonate reservoirs. In the conditions of the field under consideration, the hydraulic fracturing leads to a significant differentiation of technological efficiency indicators, which makes it expedient to study the patterns of crack formation in detail. Studies were carried out for all wells, which were considered as the objects of impact, to assess the spatial orientation of the cracks formed. The developed indirect method was used for this purpose, the reliability of which was confirmed by geophysical methods. During the analysis, it was found that in all cases, the crack is oriented in the direction of the section of the development system element characterized by the maximum reservoir pressure. At the same time, the reservoir pressure values for all wells were determined at one point in time (at the beginning of HF) using machine learning methods. The reliability of the machine learning methods used is confirmed by the high convergence with the actual (historical) reservoir pressures obtained during hydrodynamic studies of wells. The obtained conclusion about the influence of the reservoir pressure on the patterns of fracture formation should be taken into account when planning hydraulic fracturing under the conditions studied.</p></div>","PeriodicalId":19756,"journal":{"name":"Petroleum Research","volume":"8 2","pages":"Pages 226-233"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50197052","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":"Review of application of artificial intelligence techniques in petroleum operations","authors":"Saeed Bahaloo , Masoud Mehrizadeh , Adel Najafi-Marghmaleki","doi":"10.1016/j.ptlrs.2022.07.002","DOIUrl":"10.1016/j.ptlrs.2022.07.002","url":null,"abstract":"<div><p>In the last few years, the use of artificial intelligence (AI) and machine learning (ML) techniques have received considerable notice as trending technologies in the petroleum industry. The utilization of new tools and modern technologies creates huge volumes of structured and un-structured data. Organizing and processing of these information at faster pace for the performance assessment and forecasting for field development and management is continuously growing as an important field of investigation. Various difficulties which were faced in predicting the operative features by utilizing the conventional methods have directed the academia and industry toward investigations focusing on the applications of ML and data driven approaches in exploration and production operations to achieve more accurate predictions which improves decision-making processes. This research provides a review to examine the use cases and application of AI and ML techniques in petroleum industry for optimization of the upstream processes such as reservoir studies, drilling and production engineering. The challenges related to routine approaches for prognosis of operative parameters have been evaluated and the use cases of performance optimizations through employing data-driven approaches resulted in enhancement of decision-making workflows have been presented. Moreover, possible scenarios of the way that artificial intelligence will develop and influence the oil and gas industry and how it may change it in the future was discussed.</p></div>","PeriodicalId":19756,"journal":{"name":"Petroleum Research","volume":"8 2","pages":"Pages 167-182"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43544823","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}
Lawrence Opoku Boampong, Roozbeh Rafati, Amin Sharifi Haddad
{"title":"Evaluation of sour gas-low salinity waterflooding in carbonate reservoirs - A numerical simulation approach","authors":"Lawrence Opoku Boampong, Roozbeh Rafati, Amin Sharifi Haddad","doi":"10.1016/j.ptlrs.2022.10.003","DOIUrl":"10.1016/j.ptlrs.2022.10.003","url":null,"abstract":"<div><p>Although significant amount of H<sub>2</sub>S (sour gas) rich natural gas is estimated globally, but not much attention has been given to the application of H<sub>2</sub>S in the oil recovery process. Recent studies on the use of H<sub>2</sub>S in oil recovery processes showed that H<sub>2</sub>S has the potential of improving the oil recovery, and it can be even more effective than using CO<sub>2</sub> in some processes. H<sub>2</sub>S can equally dissolve in the water, react with the reservoir rock to change its surface charge, porosity, and permeability. However, previous investigations on H<sub>2</sub>S oil recovery attributed the improved oil recoveries to the higher miscibility of H<sub>2</sub>S in the oil, and the reduction in the oil viscosity. Therefore, there is limited understanding on the H<sub>2</sub>S-oil-brine-rock geochemical interactions, and how they impact the oil recovery process. This study aims to investigate the interactions between H<sub>2</sub>S, oil, and carbonate formations, and to assess how the combination of H<sub>2</sub>S and low salinity water can impact the wettability and porosity of the reservoirs. A triple layer surface complexation model was used to understand the influence of key parameters (e.g., pressure, brine salinity, and composition) on the H<sub>2</sub>S-brine-oil-rock interactions. Moreover, the effects of mineral content of the carbonate rock on H<sub>2</sub>S interactions were studied. Thereafter, the results of the H<sub>2</sub>S-oil-brine-rock interactions were compared with a study where CO<sub>2</sub> was used as the injected gas. Results of the study showed that the seawater and its diluted forms yielded identical ζ-potential values of about 3.31 mV at a pH of 3.24. This indicates that at very low pH condition, pH controls the ζ-potential of the oil-brine interface regardless of the brine's ionic strength. The study further demonstrated that the presence of other minerals in the carbonate rock greatly reduced the calcite dissolution. For instance, the calcite dissolution was reduced by 4.5% when anhydrite mineral was present in the carbonate rock. Findings from the simulation also indicated that CO<sub>2</sub> produced negative ζ-potential values for the carbonate rocks, and these values were reduced by 18.4%–20% when H<sub>2</sub>S was used as the gas phase. This implies that the H<sub>2</sub>S shifted the carbonate rock ζ-potentials towards positive. The outcomes of this study can be applied when designing CO<sub>2</sub> flooding and CO<sub>2</sub> storage where the gas stream contains H<sub>2</sub>S gas since H<sub>2</sub>S greatly influences the dissolution of the carbonate mineral.</p></div>","PeriodicalId":19756,"journal":{"name":"Petroleum Research","volume":"8 2","pages":"Pages 131-150"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42726477","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}
Tamer Hassan , Ahmad M.K. Basal , Mohammad A. Omran , Manar H. Mowafy , Mohammad A. Sarhan
{"title":"An advanced workflow to compress the uncertainties of stochastic distribution of Bahariya reservoir properties using 3D static modeling: An example from Heba Oil Fields, Western Desert, Egypt","authors":"Tamer Hassan , Ahmad M.K. Basal , Mohammad A. Omran , Manar H. Mowafy , Mohammad A. Sarhan","doi":"10.1016/j.ptlrs.2022.09.001","DOIUrl":"10.1016/j.ptlrs.2022.09.001","url":null,"abstract":"<div><p>The main objective of this paper is to construct a static model that compress the uncertainties of the stochastic distribution of the reservoir properties of the Bahariya Formation in Heba field, at the northeastern portion of the Western Desert. This model has been constructed through the integration of the interpretations of the eighteen 2D seismic sections and the analysis of well logs data for four wells (HEBA 300X, E.BAH-E−1X, E.BAH-D-1X, and HEBA 10X) drilled in the study area. This set of data was implemented in a harmonic workflow. Structural framework was the first step created on the basis of the seismic and well log interpretations. Model zonation was mainly managed by the marine flooding events took place during the Cenomanian period. The trapping faults position uncertainty has been compressed through the tying of the seismic profiles with the identified fault cuts in the well data. Effective porosity spectrum was broke up into three reservoir qualities. The results showed heterogeneous facies qualities for oil production in specific five zones in the topmost part of the Bahariya Formation. The effective porosity model was generated stochastically considering the normal distribution for each reservoir quality. Water saturation was distributed by two methods; 1) Sequential Gaussian Simulation that was co-simulated by porosity model. 2) Log-based saturation height function for each reservoir quality. This methodology provided as accurate as possible estimates for the volume calculation by quantifying the sensitivity of the important parameters such as oil contact. Additionally, the model was prepared to be used as a front end for dynamic simulation.</p></div>","PeriodicalId":19756,"journal":{"name":"Petroleum Research","volume":"8 2","pages":"Pages 205-216"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43952580","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":"A synergistic effect of zinc oxide nanoparticles and polyethylene butene improving the rheology of waxy crude oil","authors":"Toyin Olabisi Odutola","doi":"10.1016/j.ptlrs.2023.01.004","DOIUrl":"10.1016/j.ptlrs.2023.01.004","url":null,"abstract":"<div><p>This research examined the use of 75 nm zinc oxide nanoparticles (nano ZnO) and polyethylene butene (PEB) to decrease the viscosity of Nigerian waxy crude oil. The rheology of the crude oil was assessed by measuring the viscosity and shear stress of samples containing PEB at 500, 1000, 2000, 3000, 4000 or 5000 ppm and nano ZnO at 1, 2, 3 or 4 wt% between 10 and 35 °C at shear rates from 1.7 to 1020 s<sup>−1</sup>. Rheological modeling indicated that a power law pseudoplastic model was the best fit for the experimental data, giving a regression coefficient of 0.99. The addition of these inhibitors induced Newtonian fluid behavior in the crude samples such that the shear stress-shear rate relationship plots were linear at all temperatures. The optimum concentrations of the inhibitors in this study were 2000 ppm PEB (providing a 33% viscosity reduction) and 1 wt% nano ZnO (providing a 26% viscosity reduction). A combination of these additives at these concentrations provided a synergistic effect and gave a greater viscosity reduction of 41%. This work demonstrates that a blend of ZnO nanoparticles and PEB can improve the flowability of waxy crude.</p></div>","PeriodicalId":19756,"journal":{"name":"Petroleum Research","volume":"8 2","pages":"Pages 217-225"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46815666","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}
Augustine Agi , Jeffrey O. Oseh , Afeez Gbadamosi , Cheo Kiew Fung , Radzuan Junin , Mohd Zaidi Jaafar
{"title":"Performance evaluation of nanosilica derived from agro-waste as lost circulation agent in water-based mud","authors":"Augustine Agi , Jeffrey O. Oseh , Afeez Gbadamosi , Cheo Kiew Fung , Radzuan Junin , Mohd Zaidi Jaafar","doi":"10.1016/j.ptlrs.2022.07.005","DOIUrl":"10.1016/j.ptlrs.2022.07.005","url":null,"abstract":"<div><p>Seepage or loss of the mix-water from the drilling muds into the porous and permeable formations is a common problem during drilling operation. The drilling mud design requires a good knowledge of sealing integrity and all the factors influencing the mud to bridge through fractures or pore throat of exposed rocks. Loss circulation materials (LCMs) are commonly introduced into the drilling mud to prevent or minimize filtrate loss. This study investigates silica nanoparticle (SNP) derived from rice husk (RH) termed RH-SNP using the wet-milling method as an LCM in water-based mud (WBM). The impact of the RH-SNP in the enhancement of rheology and filtrate loss control properties of WBM was studied. Subsequently, the sealing integrity of the RH-SNP in a 1 mm and 2 mm simulated fracture for 7 min was determined using a stainless-steel slotted filter disk. The performance of the developed RH-SNP was compared with the widely applied nutshell. The synthesized RH-SNP at amount of 2.0 wt% significantly enhanced the yield point and plastic viscosity of the WBM by 75% and 386%, respectively, and minimized the fluid loss of the WBM by 47% at 80 °F. The enhancement is due to the particles ability to spread and interact efficiently with the WBM. With the use of 1 mm and 2 mm simulated fracture for 7 min, the mud loss volume of the base mud reduced by 50%, 66.7%, 86%, and 90% (for 1 mm) and 40%, 65.7%, 77.1%, and 80% (for 2 mm) with the inclusion of 0.5 wt%, 1.0 wt%, 1.5 wt%, and 2.0 wt% of RH-SNP, respectively. Overall, the results showed that RH-SNP enhanced the seal integrity of the drilling mud and was more resistant to deformation compared to the nutshell. The findings of this study can help for better understanding of the application of RH-SNP as a loss circulation agent owing to its superior ability to seal fractured formation compared with the often used nutshell.</p></div>","PeriodicalId":19756,"journal":{"name":"Petroleum Research","volume":"8 2","pages":"Pages 256-269"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43852704","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}