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

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.

Acid Leakoff Mechanism in Acid Fracturing of Naturally Fractured Carbonate Gas Reservoirs

2013 ◽  
Vol 868 ◽  
pp. 682-685 ◽  
Author(s):  
Lin Jing Xu ◽  
Shi Cheng Zhang ◽  
Jian Ye Mou
Keyword(s):  
Fluid Loss ◽  
Natural Fractures ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Acid Rock ◽  
Acid Fracturing ◽  
Naturally Fractured ◽  
Fractured Carbonate ◽  
Acid Leakoff ◽  
Fractured Carbonates

In acid fracturing, excessive acid leakoff is thought to be the main reason that limits fracture propagation and live acid penetration distance, so its very important to do research about acid leak-off on naturally fractured carbonates. we developed a new model in this paper to simulate acid leakoff into a naturally fractured carbonates gas reservoir during acid fracturing. Our model incorporates the acid-rock reaction on the fractured surfaces. Given the information of the Puguang gas reservoir, the model predicts acid filtration and leakoff rate over time. In this study, we found that acid leak-off mechanism in naturally fractured carbonates is much different from that in reservoirs without natural fractures. The leakoff volume is several times of nonreactive acid. Since the acid widened natural fractures, leakoff velocity increase with time firstly , then decrease. While the leakoff velocity of the nonreactive fluid decrease sustained. We also analyze other sensitivity parameters of the acid leakoff. In this model, we explain the acid leakoff mechanism in naturally fractured carbonates, and provide a more accurate calculating of fluid loss.

Study of heavy oil production ceasing options using laboratory research and mathematical modeling

2019 ◽  
pp. 32-35
Author(s):  
A.T. Zaripov ◽  
◽  
D.K. Shaikhutdinov ◽  
Ya.V. Zakharov ◽  
A.A. Bisenova ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Heavy Oil ◽  
Oil Production ◽  
Laboratory Research

scholarly journals Geomechanical modelling of cold heavy oil production with sand

Petroleum ◽  
2021 ◽  
Author(s):  
Assef Mohamad-Hussein ◽  
Pablo Enrique Vargas Mendoza ◽  
Paolo Francesco Delbosco ◽  
Claudia Sorgi ◽  
Vincenzo De Gennaro ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Oil Production

ChemInform Abstract: Technology of Synthetic Oil Production from Heavy Oil Stock and Solid Fuels

ChemInform ◽  
2015 ◽  
Vol 46 (48) ◽  
pp. no-no
Author(s):  
L. A. Gulyaeva ◽  
V. A. Khavkin ◽  
O. I. Shmel'kova ◽  
N. Ya. Vinogradova
Keyword(s):  
Heavy Oil ◽  
Oil Production ◽  
Solid Fuels ◽  
Synthetic Oil
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