Day 2 Wed, March 27, 2019最新文献

{"title":"Seismic Acquisition of Walkaway VSP and Walk Around VSP in the Xihu Sag of East China Sea Basin","authors":"Zhonglian Xiong, Zhiqiang Jiang, Yu Jiang","doi":"10.2523/IPTC-19103-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19103-MS","url":null,"abstract":"\u0000 A pre-exploration well was drilled in the Xihu Sag of East China Sea basin, and commercial oil and gas flow had been achieved. But the oil and gas bearing trap had a big depth with low closure height and small area. The resolution of seismic data acquired by towed streamer is low, so it's difficult to obtain seismic velocity precisely. There were great risk and uncertainty in description of the trap and distribution of gas-bearing sandstone, reservoir prediction of sweet spot, direct hydrocarbon indication, and reserves assessment.\u0000 In consideration of the drilling platform on the trap, seismic acquisition technique of walkaway VSP and walk around VSP were introduced, meanwhile some innovative methods in source, receivers and geometry were applied. Twenty three-component hydrophones were composed as signal receivers which had a sample interval of ten meters in the well, two straight shot lines and two loop shot lines were designed around the drilling platform. Besides, volume and depth of air gun array were optimized, and the sailing route of seismic source vessel was planned properly in order to improve the efficiency of collecting work.\u0000 The collecting work of walkaway VSP and walk around VSP was accomplished efficiently, and more than seventy kilometers VSP seismic data was achieved. Afterwards, the new data was processed finely in company with zero offset VSP data, so high resolution VSP profiles and accurate seismic velocity were obtained. Reprocess to original seismic data acquired by towed streamer was implemented on the basis of walkaway VSP and walk around VSP data. The quality of normal seismic data was improved through reprocess constrained by walkaway VSP data, and S/N and resolution were much higher than old data. So it would be credible to research the distribution of gas-bearing sandstone and direct hydrocarbon indication using the reprocessed seismic data.\u0000 It was the first time to use joint acquisition technique of walkaway VSP and walk around VSP in offshore China which was an important breakthrough. High resolution VSP seismic profiles and precise seismic velocity could be acquired, and the data was important basis for refined evaluation of pre-exploration targets. It's very necessary to popularize and utilize these new techniques further.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114508527","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":"Geomechanical Risk Evaluation for Developing Karstified Limestone Reservoir in Offshore Sarawak, Malaysia.","authors":"S. S. Ali, Kevin Ging Ern Teng, M. Jalil, M. F. Sedaralit, A. Trianto, Siti Fatimah Sarah Sagar","doi":"10.2523/IPTC-19542-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19542-MS","url":null,"abstract":"\u0000 The scope of the geomechanical study is to investigate the risk associated with different reservoir depletion strategies and to numerically simulate the geomechanical response of the reservoir rocks. The study focused on the large karstic distribution of the reservoir for the prediction of the best drilling direction and optimum well trajectories, and also to model the pore collapse behavior observed in the high porosity carbonate which will result in surface subsidence and impact the platform facilities placement.\u0000 A methodological risk evaluation approach based on numerical simulations with stringent experimental programme has been applied to the field study. The regional geological understanding and operational experience of the nearby fields have been considered for the study via extensive assessment of constitutive models relating to pore collapse. Advanced 4D geomechanical simulations were carried out to incorporate the seismic-based karstic models and to strengthen understanding of the pore collapse phenomena during reservoir depletion. The obtained prediction results were compared to nearby fields and subsequently use for wells, facilities planning and engineering considerations.\u0000 The results obtained in the study identified a few key outcomes which are being considered for detailed surface engineering design and well planning. The results have impacted the decision to place the location of the platform away from the center of the seabed subsidence bowl. The predicted reservoir compaction and subsidence described the rate and the magnitude of the subsidence which are use to design the height of the platform to mitigate potential damage induced by wave deck shearing. In addition, the distribution of karst has been mapped through seismic imaging and incorporated in the geomechanical modelling. The results are also used to determine the hazard of the weak zones in each formation and high stress anisotropy regions which are to be avoided for future well placement and to be used for well trajectory optimization. Key findings of the geomechanical-related risk have been identified and considered in the field development plan. Consequently, a Risk Ranking Criteria incorporating the results of advanced simulations and rock testing programme have been developed based on comprehensive weightage and the technical categories.\u0000 The paper offers a detailed insight on the geomechanical risk evaluation obtained using 4D finite element coupled reservoir geomechanical simulations. The study addressed the challenging development of a highly karstified limestone reservoir by offering valuable inputs for the well design and facility engineering through prediction of reservoir compaction and seabed subsidence, best drilling direction and optimum well trajectories. This will avoid potential geomechanical related hazards and ensure adequate operational safety levels.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116153581","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 Application of Distributed Temperature Sensing and CT Real-Time Downhole Flow Measurement Tool for Thermochemical Treatments","authors":"A. Al-Nakhli, Mohammed Arifin, D. Ahmed","doi":"10.2523/IPTC-19307-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19307-MS","url":null,"abstract":"\u0000 Sandstone formations can be particularly susceptible to formation damage due to organic deposits, fine migration, filter cake and formation minerals. Stimulation methods for these types of formations have typically employed mud acid due to the ability to readily dissolve both formation minerals and contaminants introduced into the wellbore/formation during drilling or remedial operations. However, hydrofluoric (HF) based fluids are corrosive, fast spending and causes formation damage by side reactions precipitations, thereby limiting the efficiency of matrix stimulation treatment.\u0000 A novel heat generating fluid has been developed as an alternative to conventional matrix stimulation for sandstone formation. The method entails triggering an exothermic chemical reaction in-situ to generate heat i.e. ~>400 °F and localized pressure. Generated heat mobilized near wellbore damage; while the pressure provided lifting energy to flowback the well, therefore, improve well injectivity. Exothermic reactants were subsequently injected via coiled tubing and allowed to soak in the treated wells. The resulting temperature and pressure increase were captured in real-time with distributed temperature sensing (DTS) coiled tubing telemetry. DTS profiling helped in understanding the in-situ exothermic reaction and avoiding post treatment production logging costs. The treatment was executed in different phases while injectivity tests were conducted after each step for each phase evaluation.\u0000 To prove the stimulation concept using thermochemicals, the treatment was applied in sandstone wells and showed superior results. DTS and downhole flow tool profiling confirmed a homogeneous treatment along the perforated interval of the well. Post treatment results showed improved well injectivity up to 50 times.\u0000 Attempts to realize consistent performance of the conventional stimulation treatments with different formulations have either been cost prohibitive or relatively ineffective. The non-acidic and heat generating fluid holds promise as an economic and a technical solution to well enhancement issues in sandstone reservoirs.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114999388","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":"Bioclastic Limestone Reservoir Characterization of an Oilfield in the Middle East","authors":"Tengfei Lin, Nai Wang, Wei-jun Wang, Nan Li, Shuang Yang, Yu-mei Liu, Junchang Dong, Qingchun Zhang, R. Guo","doi":"10.2523/IPTC-19320-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19320-MS","url":null,"abstract":"\u0000 Bioclastic limestone reservoir is playing a dominant role in the petroleum industry of Middle East. The oilfield in this paper belongs to long-axis asymmetric anticline. The S formation of Cretaceous period universally developed bioclastic limestone of carbonate platform system. It is the reservoir heterogeneity that severely limits the oilfield development.\u0000 We firstly analyze the lithofacies based on the core and thin section. Then the detailed well and seismic interpretation illustrate the sequence stratigraphy and facies analysis, and tectonic evolution are analyzed to restore sedimentary procedure from Palaeocene to late Pliocene stage. Ultimately, high quality reservoir of bioclastic limestone are depicted according to comprehensive analysis.\u0000 This paper offers reference and inspiration for bioclastic limestone reservoir: reef-beach complex and sweet spots in tidal-channel are dominant reservoirs for bioclastic limestone of Middle East.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123321348","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 Hierarchical Multiscale Framework for History Matching and Optimal Well Placement for a HPHT Fractured Gas Reservoir, Tarim Basin, China","authors":"Hongquan Chen, Changdong Yang, A. Datta-Gupta, Jianye Zhang, Liqun Chen, Liu Lei, Baoxin Chen, X. Cui, F. Shi, A. Bahar","doi":"10.2523/IPTC-19314-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19314-MS","url":null,"abstract":"\u0000 History matching of million-cell reservoir models still remains an outstanding challenge for the industry. This paper presents a hierarchical multi-scale approach to history matching high resolution dual porosity reservoir models using a combination of evolutionary algorithm and streamline method. The efficacy of the approach is demonstrated through application to a high pressure high temperature (HPHT) fractured gas reservoir in the Tarim basin, China with wells located at an average depth of 7500 meters.\u0000 Our proposed multi-scale history matching approach consists of two-stages: global and local. For the global stage, we calibrate coarse-scale static and dynamic parameters using an evolutionary algorithm. The global calibration uses coarse-scale simulations and applies regional multipliers to match RFT data, well bottom hole pressures, and field average pressure. For the local stage, we calibrate fracture permeability using streamline based sensitivities to further match well bottom-hole pressures. The streamlines are derived from the fracture cell fluxes and the sensitivities are analytically computed for highly compressible flow. The sensitivities are validated by comparison with the pertubation method.\u0000 The proposed hierarchical multiscale history matching workflow is applied to a faulted and highly fractured deep gas reservoir in the Tarim basin, China. The excessive well cost arising from the large well depth (7500 meters) and high pressure (18000 psi) necessitates optimal field development with limited number of wells. The fracture properties of dual porosity model are upscaled from a highly dense discrete fracture network model generated based on well data and seismic attributes. The history matching includes RFT data, static pressure data and flowing bottom-hole pressure data in producing wells. Field average pressure and RFT (static pressure) data were well matched during the global stage using coarse scale models while flowing bottom-hole pressure is further matched during the local stage calibration using fine scale models. Streamline method has been applied previously mainly to incompressible or slightly compressible flow. However in this application, the results show that the modified streamline-based sensitivity can also significantly reduce data misfit for highly compressible flow. The history matched models are used to visualize well drainage volumes using streamlines. The well drainage volumes in conjunction with static reservoir properties are used to define a ‘depletion capacity map’ which is then used for optimal infill well placement.\u0000 The novelty of our approach lies in the application of streamlines derived from dual porosity finite-difference simulation to facilitate history matching and well placement optimization in a tight gas reservoir. The newly developed streamline-based analytical sensitivities are suitable for highly compressible flow. To our knowledge, this is the first time streamlines have been used to facil","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"132 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123444790","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":"Monte Carlo Optimization for Site Selection of Process Facilities in Oilfields Considering Environment","authors":"Bohong Wang, Qi Liao, Jianqin Zheng, Meng Yuan, H. Zhang, Yongtu Liang","doi":"10.2523/IPTC-19153-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19153-MS","url":null,"abstract":"\u0000 The site selection of the facilities in oilfields is one of the important issues for surface engineers. In the progressive development of oilfields, new wells are explored and developed, and new process facilities (PFs) should be constructed to gather and process the fluid from these new wells. The emission of the PFs will affect the surrounding environment, including water sources, forests, and human settlements. Thus, the environment should be considered as one of the key aspects in the design process of facilities. Different locations of facilities in the oilfields will affect both the construction cost and environmental cost. Thus, a balance has to be found. In addition, the uncertainty of production rate of well fluid poses a great challenge to this problem. To solve the above problem, this paper provides a systematic methodology.\u0000 The objective function consists two parts: construction costs and environmental cost. The solving algorithm has involved three layers of looping programming to calculate the value of objective function. First the weather conditions are generated by the Monte Carlo method, then the second loop is for the study areas, and the third loop is for the new facilities locations. After all the loops of iterations are completed, the objective functions are calculated, and the influence of the environment can be evaluated. Finally, the best solution can be obtained.\u0000 The effectiveness of the proposed method is demonstrated through a design problem in an oilfield. The candidate locations for PFs are previously determined, and the optimal construction plan is solved by our method. The quantitative influence on the environment to these candidate locations can be evaluated. After determining the coefficient of the construction cost and the environmental cost, the best locations for the process facilities with the lowest total cost can be determined.\u0000 A multi-objective model for the site selection of process facilities in oilfields is proposed, which has not been done by existing literatures. The construction cost and surrounding environment are both considered in the model. This work has the potential to serve as a decision-support tool for surface engineers in oilfields.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"162 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123462262","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":"Design for Well Longevity: Optimizing Cement Barrier Quality in UGS Wells","authors":"Fei Gao, Rui Wang, Hongsheng Su, S. Zhong, Yabin Guo, S. Taoutaou","doi":"10.2523/IPTC-19478-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19478-MS","url":null,"abstract":"\u0000 A design approach was developed to obtain an optimum annulus cement barrier during well construction of a 29-well underground gas storage (UGS) project to maximize the longevity of the UGS wells in the years that followed in production state. The effectiveness of this approach was verified by multi-year post-job surface and subsurface field data from all the wells from the time the wells were put into production in this project.\u0000 The UGS wells are adjacent to a residential area, making reliable well integrity of great significance. To facilitate this, the cementing design for an entire well was prepared to obtain good and durable zonal isolation. The design focused on long-term well integrity and longevity rather than short-term effectiveness. First, the cementing technique was reviewed so that best practice for a high-quality cementing operation was applied in this project. Second, an advanced third-interface pulse-echo cement evaluation logging tool was adopted for better understanding of the cementing job results and to use the indications for subsequent job improvement. The tool measures the state of annulus material and casing standoff, which considerably impacts the cementing quality. Third, a high-performance flexible/expandable (HPFE) cement system with engineered mechanical properties was introduced to the project. With a specialized cement stress simulation software, the mechanical properties of the cement were optimized to deal with the downhole varying pressures and temperatures the cement would see during completion and production. Temperature change was predicted to fluctuate between 69 and 81°C and pressure between 17 MPa and 34 MPa. From the 5 years of production of the UGS wells, downhole temperature and pressure were recorded. Pressure values were within the predicted range. The temperature was higher than expected, but the designed set cement was robust enough to deal with the higher temperature.\u0000 In all, 29 UGS wells were cemented from 2011 to 2016 in this campaign. Due to the continuous effort of improving the cementing quality through the iterations of optimizing job program, the cement bond log result was better in the later 4 years of the project compared to the first 2 years. In June 2013, some of the wells were put into production and gas injection initiated. In the following 5 years, the whole storage block was gradually put into production up to its full capacity. We conducted a post-job numerical cement integrity study based on the acquired field data from the last 5 years with the measured set-cement mechanical properties. The result indicates the cement barrier can remain intact under the varying downhole conditions. This is evidenced by the post-job production behavior, which was being monitored during the gas injection and withdrawal cycles and no sustained casing pressure (SCP) problem was ever reported during the process.\u0000 The design for the cementing program focused on the well barrier quality from the beginn","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123820352","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":"Comparative Analysis of Machine Learning Based Feature Selection Approach for Carbonate Reservoir Cementation Factor Prediction","authors":"F. Anifowose, C. Ayadiuno, Faisal Rashedan","doi":"10.2523/IPTC-19330-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19330-MS","url":null,"abstract":"\u0000 A key component of the fourth industrial revolution is data integration. However, this comes with a major challenge: handling increased input feature dimensionality. Multivariate feature space increases model complexity, memory utilization, and computational intensity, thereby reducing model performance. A pragmatic approach to input feature space reduction is therefore required. This paper presents a comparative study of the performance of a nonlinear feature selection methodology based on fuzzy ranking (FR). The FR algorithm is extracted from a segment of Fuzzy Logic, an existing machine learning technique. The performance of this feature selection algorithm is tested and validated with respect to the prediction of cementation factor as a log from wireline measurements using machine learning techniques. Cementation factor is denoted by the exponent m in Archie's equation. A subset of the log data selected by the FR algorithm is automatically fed into artificial neural network (ANN) and support vector machine (SVM) models to build FR-ANN and FR-SVM hybrid learning models. A multivariate linear regression (MLR) model is also implemented. The performance of the hybrid models is compared to those of MLR, ANN and SVM without the feature selection procedure. We further compare the outcome with ANN and SVM fed with linearly correlated input features. The hybrid learning methodology is driven by patterns discovered in the data and eliminates subjective human bias in the choice of the input features. It also takes into consideration the possible nonlinear relationship between the wireline logs and m. The FR-ANN model shows improved performance over the other models with the highest correlation coefficient and lowest root mean squared error. The performance of the FR-ANN hybrid model demonstrates the efficiency of the proposed nonlinear feature selection hybrid methodology. A future work will apply this approach to high dimensional, integrated data types from many wells. We expect that the outcome will significantly improve the prediction accuracy and further impact reservoir models using the predicted properties.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125790198","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":"Case Stories of Horizontal Wells in Offshore Fluvial Oil Reservoir","authors":"Hongfu Shi, Yong Hu, Yifan He, Qiang Sun, Junshou Zhao","doi":"10.2523/IPTC-19206-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19206-MS","url":null,"abstract":"\u0000 Fluvial facies reservoirs account for 60% of the reserves in Bohai oilfield. The effective development of such reservoirs plays a very important role in long-term stable production of Bohai oilfield. There are many challenges including: poor reserve, large well spacing, large lateral changes, poor connectivity, heterogeneity, unfavorable viscosity, low structure amplitude and strong bottom water. Horizontal wells are widely used in these reservoirs, especially in the edge or bottom water reservoir and the narrow channel reservoir in Bonan area. Many cases of horizontal wells design, implementation, well pattern optimization and water flooding management were presented to improve the recovery rate of fluvial oil reservoirs. The technique has been widely used in ten fluvial oil fields in Bohai, and has enhanced the recovery rate of by 3% and achieved remarkable technical and economic effects.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129484639","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":"Application of Fuzzy Control Theory in the Study of the Macroscopic Remaining Oil Distribution for a Mature Sandstone Reservoir in the Tarim Oilfield, China","authors":"Jian Sun, Chenyang Li, Zekai Zhang, L. Ren, Qi Li, Mingqiang Chen, Bo Zhang, K. Tang","doi":"10.2523/IPTC-19263-MS","DOIUrl":"https://doi.org/10.2523/IPTC-19263-MS","url":null,"abstract":"\u0000 Research on macroscopic remaining oil distribution (MROD) has become a worldwide issue and not yet been satisfactorily solved in oil industry. At present, the commonly used methods for determining MROD are heavy workload, long time consuming and greatly influenced by human factors. In the research of MROD, geological factors are uncontrollable and development factors are controllable. Therefore, under certain development conditions, geological factors determine the MROD. This paper mainly studies MROD in geological factors.\u0000 The new approach is based on development geological principles. It uses fuzzy control theory to predict MROD. Firstly, according to structural location from high to low and clay content from much to less, the structural location parameters and sedimentary microfacies parameters are fuzzified into 5 grades respectively. Secondly, according to the hydrocarbon potential from good to poor, the oil and gas universe is fuzzified into 5 grades. Finally, fuzzy control rules were established. It can be calculated by characteristic expansion method. Complete governing equations are provided and the method is described in detail to permit readers to replicate all results.\u0000 The method of using fuzzy control theory to predict MROD has been successfully applied in Tarim oilfield. According to the range of tectonic height and clay content, the membership degrees of structural location parameters and sedimentary microfacies parameters are assigned respectively. LN2-G well in research region is chosen as an example for study. The characteristic coefficients corresponding to LN2-G well under different structure and sedimentary conditions are respectively obtained. Through the fuzzy control statement, and combining the principle of maximum membership degree, the oil level in the target formation of well LN2-G can be calculated, which value is 5, corresponding to the oil layer. Then we use the existing exploration wells in research region, and use the above method to calculate them respectively. Based on the calculated results, we draw the remaining oil distribution level range prediction plan. Finally, we selected 3 wells to verify the accuracy of the prediction. It shows that the reservoirs drilled by LN2-X, LN2-Y and LN2-Z wells are water layer, water layer and poor oil layer, respectively. The actual drilling results of these 3 wells are water layer, water layer and oil-bearing water layer, which are completely consistent with the prediction results.\u0000 This research can accurately forecast the MROD based on the analysis of the essential factors (geological factors) affecting the MROD. The method is convenient and economical, which provides a reliable basis for the remaining oil development.","PeriodicalId":105730,"journal":{"name":"Day 2 Wed, March 27, 2019","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129507101","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}