What We Have Learned on Stimulating Intensely Naturally Fractured HPHT Deep Sandstone Comparing Acid-Fracturing, Fracturing and Non-Acid Stimulation

2016 ◽  
Author(s):  
Mingguang Che ◽  
Yonghui Wang ◽  
Suzhen Li ◽  
Rui Gao ◽  
Liao Wang ◽  
...  
Keyword(s):  
Acid Fracturing ◽  
Naturally Fractured

Predicting the Productivity Enhancement After Applying Acid Fracturing Treatments in Naturally Fractured Reservoirs Utilizing Artificial Neural Network

2021 ◽  
Author(s):  
Amjed Mohamed Hassan ◽  
Murtada Saleh Aljawad ◽  
Mohamed Ahmed Mahmoud
Keyword(s):  
Neural Network ◽  
Correlation Coefficient ◽  
Fractured Reservoirs ◽  
Naturally Fractured Reservoirs ◽  
Percentage Error ◽  
Reservoir Properties ◽  
Productivity Improvement ◽  
Acid Fracturing ◽  
New Correlation ◽  
Naturally Fractured

Abstract Acid fracturing treatments are conducted to increase the productivity of naturally fractured reservoirs. The treatment performance depends on several parameters such as reservoir properties and treatment conditions. Different approaches are available to estimate the efficacy of acid fracturing stimulations. However, a limited number of models were developed considering the presence of natural fractures (NFs) in the hydrocarbon reservoirs. This work aims to develop an efficient model to estimate the effectiveness of acid fracturing treatment in naturally fractured reservoirs utilizing an artificial neural network (ANN) technique. In this study, the improvement in hydrocarbon productivity due to applying acid fracturing treatment is estimated, and the interactions between the natural fractures and the induced ones are considered. More than 3000 scenarios of reservoir properties and treatment parameters were used to build and validate the ANN model. The developed model considers reservoir and treatment parameters such as formation permeability, injection rate, natural fracture spacing, and treatment volume. Furthermore, percentage error and correlation coefficient were determined to assess the model prediction performance. The proposed model shows very effective performance in predicting the performance of acid fracturing treatments. A percentage error of 6.3 % and a correlation coefficient of 0.94 were obtained for the testing datasets. Furthermore, a new correlation was developed based on the optimized AI model. The developed correlation provides an accurate and quick prediction for productivity improvement. Validation data were used to evaluate the reliability of the new equation, where a 6.8% average absolute error and 0.93 correlation coefficient were achieved, indicating the high reliability of the proposed correlation. The novelty of this work is developing a robust and reliable model for predicting the productivity improvement for acid fracturing treatment in naturally fractured reservoirs. The new correlation can be utilized in improving the treatment design for naturally fractured reservoirs by providing quick and reliable estimations.

Acid Fracturing Experience In Naturally Fractured – Heavy Oil Reservoir, Bati Raman Field

2021 ◽  
Author(s):  
Mustafa Erkin Gozel ◽  
Serkan Uysal ◽  
Cosan Ayan ◽  
Ugur Yuce ◽  
Egemen Ozturk ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Laboratory Tests ◽  
Reaction Rates ◽  
Carbonate Reservoir ◽  
Production Performance ◽  
Total Production ◽  
Acid Fracturing ◽  
Wide Range ◽  
Fracture Closure ◽  
Naturally Fractured

Abstract Bati Raman field, with an original oil in place of 1.85 billion barrels, is a naturally fractured carbonate reservoir containing 9-13 °API extra heavy oil with viscosities varying from 300 to 600 cp. Not only a wide range of pilot EOR schemes including gas, thermal and chemical methods, but also novel IOR applications have been tried in the field. CO2 injection was a game changer for this reservoir which has been the main drive mechanism since 1987. Since then, various techniques are applied to further improve the production performance of the field. This study focuses on the design and outcome of the pilot acid fracturing treatments in selected three wells in the tighter and less fractured southeastern part of the reservoir. State of the art planning included full evaluation of well integrity, cement bond and open hole logs, geomechanics studies augmented with rock mechanics laboratory tests. Laboratory tests were also conducted focusing on sludge/emulsion forming tendencies and acid reaction rates. Using these results, expected fracture dimensions were predicted along with production forecasts. In all wells, pre-frac calibration tests were conducted to assess stress conditions and fracturing parameter optimization. The treatments were then executed, improving the procedure between each well for acid fracturing. Injections schemes were operationally efficient and various diversion techniques were used to mitigate the presence of naturally fractured zones. Pre and post-job temperature logs helped to evaluate each treatment. The results from the wells were very positive; total production rate increased about fivefold, observed within one month after the treatments. No considerable change in water or CO2 production in the wells was observed which had been one of the most important objectives during the candidate selection process. One well was suspended, which turned out to be one of the producers of the field after acid fracturing treatment. Each well had a different post-frac production performance because of its geological characteristics and flow dynamics, making the study more valuable for better understanding of the process. The wells are still on critical observation to assess the nature of the created fractures and their longevity in the long run. Even after twelve to fifteen months of production, which is the breaking point period for fracture closure, the overall production level of the wells was double compared to pre-frac rates. One well still has a fracture dominated production while other two changed back into its pre-frac rates. Based on these results, acid fracturing campaign was extended in the area which is currently under evaluation.

scholarly journals Acid Fracturing Optimizing Design and Application in Deep Naturally Fractured Carbonate

2021 ◽  
Vol 687 (1) ◽  
pp. 012114
Author(s):  
Mingguang Che ◽  
Yonghui Wang ◽  
Jianxin Peng ◽  
Changlin Zhou ◽  
Kai Dong
Keyword(s):  
Acid Fracturing ◽  
Naturally Fractured ◽  
Fractured Carbonate ◽  
Optimizing Design ◽  
Design And Application

Optimization of Acid Fracturing to Improve Heavy Oil Production in Naturally Fractured Carbonates

2003 ◽  
Author(s):  
Xugang Wang ◽  
Honglan Zou ◽  
Xingquan Zheng ◽  
Fuxiang Zhang ◽  
Yonghong Fan ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Oil Production ◽  
Acid Fracturing ◽  
Naturally Fractured ◽  
Fractured Carbonates

scholarly journals Development of Acid Fracturing Model for Naturally Fractured Reservoirs

2019 ◽  
Vol 34 (04) ◽  
pp. 735-748
Author(s):  
Assiya Ugursal ◽  
Ding Zhu ◽  
Alfred Daniel Hill
Keyword(s):  
Fractured Reservoirs ◽  
Naturally Fractured Reservoirs ◽  
Acid Fracturing ◽  
Naturally Fractured
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