Plugging Technology for HTHP Wells in the Yingqiong Basin of the South China Sea

HAN Cheng1 HUANG Kaiwen1 LUO Ming1 LIU Xianyu1 DEND Wenbiao1

(1.CNOOC China Limited, Shenzhen Branch, Zhanjiang, Guangdong, China 524057)

【Abstract】The Yingqiong Basin in the western South China Sea is characterized by complex geological conditions, high bottomhole temperatures and pressures, and lost circulation which occurs frequently during drilling into the target layer. In order to solve the problem of frequent lost circulation in the target layer, the main causes of lost circulation were analyzed; the idea of combining the high temperature resistant rigid plugging materials with high temperature resistant elastic plugging materials was followed; and a plugging slurry was prepared by adding DXD (high-temperature resistant rigid plugging material) and TXD (high-temperature resistant elastic graphite plugging material) into drilling fluid. The performance evaluation showed that the density of plugging slurry could reach 2.40 kg/L and the temperature resistance could reach 200 °C. The DXD could form bridges in the induced fractures, while the TXD could enter the residual pores of induced fractures under pressure difference, preventing the induced fractures from further opening and expanding, blocking the induced fractures and improving the pressure-bearing capacity of formation. This plugging slurry was applied in several high temperature and high pressure (HTHP) wells in the Yingqiong Basin with the success rate of plugging increasing from 30% to 80%, indicating that the plugging slurry could block the induced fractures in the target layer of the Yingqiong Basin, improve the pressure-bearing capacity of formation and the success rate of plugging, and solve the problem of frequent lost circulation in the target layer.

【Keywords】 HTHP well; lost circulation; induced fractures; plugging agent; Yingqiong Basin; the South China Sea;

【DOI】

【Funds】 National Science and Technology Major Project of “HTHP Gas Enrichment Principle and Key Exploration and Development Technologies in the Yingqiong Basin (Phase III)” (2016ZX05024-005) CNOOC’s Major Scientific Research Project of “Study and Application of HTHP Drilling and Completion Fluids and Cementing Technology in the Yingqiong Basin” (CNOOC-KJ 135ZDXM 24 LTD ZJ 02)

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    References

    [1] LUO Ming, HAN Cheng, CHEN Haodong, et al. Plugging technology for HTHP wells in Western South China Sea [J]. Oil Drilling & Production Technology, 2016, 38 (6): 801–804 (in Chinese).

    [2] HUANG Yi, SHENG Yanan, GUAN Zhichuan, et al. Quantitative risk assessment of wellbore stability of Yingqiong Basin [J]. Fault-Block Oil & Gas Field, 2018, 26 (3): 380–384 (in Chinese).

    [3] ZHAO Wei, LIN Yong, LI Bo, et al. Research on adaptive mud loss control and protection technology used for induced fractures [J]. Drilling Fluid & Completion Fluid, 2012, 29 (4): 12–15 (in Chinese).

    [4] LIU Sihai, CUI Qingdong, LI Weiguo. Circulation loss characteristics and challenges and measures to plug under pressure in Northeast Sichuan Area [J]. Petroleum Drilling Techniques, 2008, 36 (3): 20–23 (in Chinese).

    [5] ZHAO Wei, LI Bo, GAO Yunwen, et al. Study of lost circulation protection and control drilling fluid for induced cracks [J]. Oilfield Chemistry, 2013, 30 (1): 1–4 (in Chinese).

    [6] TIAN Jun, LIU Wentang, LI Xudong, et al. Development and application of rapid filtration and consolidation lost circulation material ZYSD [J]. Petroleum Drilling Techniques, 2018, 46 (1): 1–8 (in Chinese).

    [7] MA Xinzhong, ZHANG Shenshen, FANG Jing, et al. Study on mud loss control under pressure in drilling fractured carbonate reservoirs in Block Tahe 10 [J]. Drilling Fluid & Completion Fluid, 2018, 35 (5): 36–40 (in Chinese).

    [8] ZHANG Huolan, PEI Jianxiang, ZHANG Yingzhao, et al. Over-pressure reservoirs in the mid-deep Huangliu Formation of the Dongfang Area, Yinggehai Basin, South China Sea [J]. Petroleum Exploration and Development, 2013, 40 (3): 284–293 (in Chinese).

    [9] JIA Lichun, CHEN Mian, ZHANG Wei, et al. A study of induced crack lost circulation plugging mechanism [J]. Drilling Fluid & Completion Fluid, 2013, 30 (5): 82–85, 101 (in Chinese).

    [10] GUO Hong, LI Xiaorong, ZHANG Huisen. A plugging cracks in ultra low permeability oilfield system research and application [J]. Science Technology and Engineering, 2012, 12 (33): 8835–8840 (in Chinese).

    [11] YAN Peiyu, ZHOU Yongxiang, YANG Zhenjie. Microstructure and sealing mechanism of high-temperature sealant [J]. Journal of Materials Science and Engineering, 2006, 24 (6): 811–814 (in Chinese).

    [12] CHEN Liang, WANG Lifeng, CAI Lishan, et al. High pressure circulation lost techniques for salt beds in the Tahe Oilfield [J]. Petroleum Drilling Techniques, 2006, 34 (4): 63–66 (in Chinese).

    [13] WANG Gui, PU Xiaolin. Plugging mechanism of drilling fluid by enhancing wellbore pressure [J]. Acta Petrolei Sinica, 2010, 31 (6): 1009–1012 (in Chinese).

    [14] LIN Yongxue, WANG Weiji, JIN Junbin. Key drilling fluid technology in the ultra deep section of Well Ying-1 in the Shunbei Oil and Gas Field [J]. Petroleum Drilling Techniques, 2019, 47 (3): 113–120 (in Chinese).

This Article

ISSN:1001-0890

CN:11-1763/TE

Vol 47, No. 06, Pages 15-20

November 2019

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Article Outline

Abstract

  • 1 Analysis of causes of lost circulation
  • 2 Plugging practice and performance evaluation
  • 3 Field applications
  • 4 Conclusions and suggestions
  • References