scholarly journals Study on Well Selection Method for Refracturing Horizontal Wells in Tight Reservoirs

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4202
Author(s):  
Qihong Feng ◽  
Jiawei Ren ◽  
Xianmin Zhang ◽  
Xianjun Wang ◽  
Sen Wang ◽  
...  
Keyword(s):  
Horizontal Wells ◽  
Engineering Properties ◽  
Tight Oil ◽  
Well Test ◽  
Tree Model ◽  
Factors Affecting ◽  
Comprehensive Index ◽  
Tight Reservoirs ◽  
Potential Evaluation ◽  
Selection Of

Refracturing technology is one of the key technologies to recover the productivity of horizontal wells in tight oil reservoirs, and the selection of best candidate wells from target blocks is the basis of this technology. Based on the refracturing production database, this paper analyzes the direct relationship between geological data, initial fracturing completion data, and dynamic production data, and the stimulation effect of refracturing. Considering the interaction among multiple factors, the factors affecting the stimulation effect of refracturing are classified and integrated, and a comprehensive index including geology, engineering, and production is constructed, making this index meaningful both for physical and engineering properties. The XGBoost decision tree model is established to analyze the weight of influence for the comprehensive index of geology, engineering, and production in predicting the stimulation effect of refracturing. A comprehensive decision index of refracturing well selection is formed by combining the above three for performing a fast selection of horizontal candidate wells for fracturing. Taking a horizontal well test area in Songliao Basin as an example, the target wells of refracturing are selected by this method, and field operation is carried out, and a good stimulation effect is achieved. The results show that the comprehensive decision-making index constructed by this method is reliable and has certain guiding significance for well selection and stimulation potential evaluation of tight oil reservoir.

A New Productivity Prediction Hybrid Model for Multi-Fractured Horizontal Wells in Tight Oil Reservoirs

2021 ◽  
Author(s):  
Liang Tao ◽  
Jianchun Guo ◽  
Zhijun Li ◽  
Xuanyi Wang ◽  
Shubo Yang ◽  
...  
Keyword(s):  
Hybrid Model ◽  
Evaluation System ◽  
Horizontal Wells ◽  
Oil Reservoirs ◽  
Tight Oil ◽  
Factors Affecting ◽  
Tight Oil Reservoirs ◽  
Volume Fracturing ◽  
Fractured Horizontal Wells ◽  
Productivity Prediction

Abstract Single well productivity is an important index to evaluate the effect of volume fracturing. However, there are many factors affecting the productivity of Multi-fractured horizontal wells (MFHWs) in unconventional reservoirs and the relationship is complex, which makes productivity prediction very difficult. In this paper, taking the tight oil reservoir in Songliao Basin as the research object, a new mixed model of initial cumulative oil production of MFHWs was established, which can consider the geological factors and volume fracturing factors at the same time. Firstly, based on the big data, the multi-level evaluation system was established by using the analytic hierarchy process (AHP). Then, the weight factor was calculated to uncover key factors that dominate productivity of MFHWs. Finally, the fuzzy logic method was used to calculate the Euclidean distance and quantitatively predict the production of any horizontal wells. The simulation results shown that: the order of the main factors affecting production in the study area was horizontal section sandstone length, number of stages, formation pressure, proppant amount, net pay thickness, permeability, porosity, oil saturation, fracturing fluid volume. The hybrid model has been applied to the productivity prediction of 185 MFHWs in tight oil reservoirs in China, the prediction error was less than 5%. The new model can be used to predict production for MFHWs quickly and economically.

A New Re-Fracturing Candidate Selection Method for Multi-Fractured Horizontal Well in Tight Oil Reservoirs

2021 ◽  
Author(s):  
Liang Tao ◽  
Xiaozhuo Zhang ◽  
Shubo Yang ◽  
Sheng Xian ◽  
Yuhang Zhao ◽  
...  
Keyword(s):  
Dynamic Effect ◽  
Production Performance ◽  
Oil Reservoirs ◽  
New Method ◽  
Tight Oil ◽  
Factors Affecting ◽  
Fitting Method ◽  
Tight Oil Reservoirs ◽  
Fractured Horizontal Wells ◽  
Selection Of

Abstract The selection of refracturing candidate is the primary challenge of refracturing technology. There are many factors affecting the selection of refracturing candidate for multi-fractured horizontal wells (MFHWs) and the relationship between each factor is very complicated, which makes it very difficult to select the optimal wells. A new method combining initial completion efficiency and production performance was proposed in this study to solve this problem. First, the fracture parameters were obtained by fitting method to evaluate the initial completion efficiency. Then, the geological model was established by the method of reservoir numerical simulation to evaluate the dynamic effect of production. Finally, the potential of refracturing was evaluated. The new method has been successfully applied to 30 wells of the tight oil reservoirs in Songliao Basin China. The average daily oil production was 18.5 tons/day after refracturing treatment. This research could provide significant guidance for the development of tight oil reservoirs.

Selection criteria for slurry trench cutoffs

1983 ◽  
Vol 10 (3) ◽  
pp. 527-537
Author(s):  
M. D. Haug ◽  
Paul Kozicki
Keyword(s):  
Selection Process ◽  
Selection Procedure ◽  
Poor Performance ◽  
Engineering Properties ◽  
Cutoff Wall ◽  
Factors Affecting ◽  
Wide Range ◽  
Slurry Trench ◽  
Open Trench ◽  
Selection Of

Slurry trench cutoff walls have been employed for over three decades and are becoming increasingly popular for controlling seepage of groundwater and hazardous wastes. They are also gaining acceptance for construction of underground facilities. The technique involves the excavation of a narrow trench in the presence of a bentonitic fluid or slurry. The slurry acts to support the open trench until it is backfilled with an impermeable material. The increase in popularity of these walls has been aided by the development of new construction techniques. These techniques offer the designer a wide range of engineering properties for the cutoff wall. However, there are few published guidelines on the selection of slurry trench cutoffs. This has resulted in situations where the cutoff wall selected was originally designed for a totally different application. The net effect in these cases has been poor performance and an unsatisfactory cutoff wall.This paper examines the principal methods of constructing slurry trench cutoffs, establishes their engineering characteristics, and presents a procedure for selecting a slurry trench cutoff. The factors which influence the selection are identified and discussed. The methodology of the selection process is reviewed with an example. This review and examination of the selection procedure demonstrates that it is an effective method of compiling and systematically analyzing the relevant factors affecting selection of slurry trench cutoffs.

Selection of factors affecting increase of non-oil export

2018 ◽  
Vol 13 (1) ◽  
pp. 45-52
Author(s):  
Aynura Manaf kizi Ismayilova ◽  
Keyword(s):  
Factors Affecting ◽  
Oil Export ◽  
Selection Of

Regional, institutional and individual factors affecting selection of minimally invasive nephroureterectomy in Japan: A national database analysis

2012 ◽  
Vol 20 (7) ◽  
pp. 695-700 ◽  
Author(s):  
Toru Sugihara ◽  
Hideo Yasunaga ◽  
Hiromasa Horiguchi ◽  
Tetsuya Fujimura ◽  
Hiroaki Nishimatsu ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
National Database ◽  
Individual Factors ◽  
Database Analysis ◽  
Factors Affecting ◽  
Selection Of

scholarly journals Ball sealer tracking and seating of temporary plugging fracturing technology in the perforated casing of a horizontal well

2021 ◽  
pp. 014459872110204
Author(s):  
Wan Cheng ◽  
Chunhua Lu ◽  
Guanxiong Feng ◽  
Bo Xiao
Keyword(s):  
Critical Parameter ◽  
Fluid Velocity ◽  
Stable State ◽  
Horizontal Wells ◽  
Terminal Velocity ◽  
Injection Rate ◽  
Fracturing Fluid ◽  
Perforation Hole ◽  
Horizontal Wellbore ◽  
Tight Reservoirs

Multistaged temporary plugging fracturing in horizontal wells is an emerging technology to promote uniform fracture propagation in tight reservoirs by injecting ball sealers to plug higher-flux perforations. The seating mechanism and transportation of ball sealers remain poorly understood. In this paper, the sensitivities of the ball sealer density, casing injection rate and perforation angle to the seating behaviors are studied. In a vertical wellbore section, a ball sealer accelerates very fast at the beginning of the dropping and reaches a stable state within a few seconds. The terminal velocity of a non-buoyant ball is greater than the fluid velocity, while the terminal velocity of a buoyant ball is less than the fluid velocity. In the horizontal wellbore section, the terminal velocity of a non-buoyant or buoyant ball is less than the fracturing fluid flowing velocity. The ball sealer density is a more critical parameter than the casing injection rate when a ball sealer diverts to a perforation hole. The casing injection rate is a more critical parameter than the ball sealer density when a ball sealer seats on a perforation hole. A buoyant ball sealer associated with a high injection rate of fracturing fluid is highly recommended to improve the seating efficiency.

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