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Pore pressure prediction in the Dongfang 1-1 gas field, Yinggehai basin

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Category: Geology

Last Updated on 11 July 2014

Published on 11 May 2014

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Authors:

Chen Zijian, China University of Petroleum, State Key Laboratory of Petroleum Resource and Prospecting, Beijing, China

Deng Jingen, China University of Petroleum, State Key Laboratory of Petroleum Resource and Prospecting, Beijing, China

Yu Baohua, China University of Petroleum, State Key Laboratory of Petroleum Resource and Prospecting, Beijing, China

Yan Chuanliang, China University of Petroleum, State Key Laboratory of Petroleum Resource and Prospecting, Beijing, China

Abstract:

Dongfang 1-1 gas field is a high temperature and high pressure area. An accurate pore pressure prediction is very important for safe drilling in this area. The authors have analyzed and classified the overpressure mechanisms on the base of loading and unloading, which are the relationships of vertical effective stress and acoustic velocity. Then, the logging responses for different overpressure mechanisms have been discussed. Based on the above, the new method of pore pressure prediction by means of the DT-density crossplot and DT-density-depth crossplot has been proposed. The method has been applied to analyze the overpressure causes and predict a high temperature and high pressure well in DF1-1 gas filed, Yinggehai Basin. The results show that the overpressure in DF1-1 gas filed is caused by three factors: disequilibrium compaction, aquathermal expansion and hydrocarbon generation. Their contribution to the overpressure in different formations is different. By using the DT-density crossplot and the DT-density-depth crossplot the contribution can be distinguished and feasible prediction model can be chosen. The authors have proved that the Eaton method is only suitable for disequilibrium compaction; but the Bowers method is effective for the overpressure caused by disequilibrium compaction or fluid volume expansion. This method improves the pore pressure prediction accuracy in DF 1-1 gas filed effectively. It is of importance to the drilling engineering.

References:

1. Wang Zhenfeng and Huang Baojia (2008), “Dongfang 1-1 gas field in the mud diapir belt of the Yinggehai Basin, South China Sea”, Marine and Petroleum Geology, no. 25, pp. 445–455.

2. Hao Fang, Zou Huayao and Huang Baojia (2003), “Natural gas generation model and its response in accumulated fluids in the Yinggehai basin”, Science In China, (Series D), Vol. 45, no.11, pp. 1103–1110.

3. Hao, F., Sun, Y.C. and Li, S.T. (1995), “Overpressure retardation of organic-matter maturation and hydrocarbon generation:
A case study from the Yinggehai and Qiongdongnan basins, offshore South China Sea”, AAPG Bulletin, no.79, pp. 551–562.

4. Ye Zhi, Fan Hong-hai and Cai Jun (2012), “Investigation and application of a discrimination method for abnormal high formation pressure forming mechanism”, Journal of China University of Petroleum, no.36 (3), pp. 102–107.

5. Ben A. Eaton (1975), “The Equation for Geopressure Prediction from Well Logs”, The 50^th aunnual fall meeting of the society of Petroleum Engineers of AIME, Dallas, Texas, Sept. 28-Oct.1, 1975, SPE5544.

6. Zhang Qiming (1996), “Overpressure system and hydrocarbon accumulation in the Yinggehai Basin (in Chinese)”, China Offshore Oil and Gas (Geology), no.10(2), pp. 65–75.

7. Xie Yuhong (2011), “Models of pressure prediction and new understanding of hydrocarbon accumulation in the Yinggehai Basin with high temperature and super-high pressure”, Natural Gas Industry, no.31(12), pp. 21–25.

8. Glenn L. Bowers (1995), “Pore Pressure Estimation From Velocity Data: Accounting for Overpressure Mechanisms Besides Undercompaction”, SPE Drilling & Completion, June 1995, SPE 27488.

9. Badri, M.A., Sayers, C. and Hussein, R.A. “Pore Pressure Prediction Data Using Seismic Velocities and Log Data in the Offshore Nile Delta”, Egypt. SPE 68195.

10. Glenn Bowers (1999), State of the Art in Pore Pressure Estimation, Knowledge Systems, Inc.

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