An Analysis on Wellbore Collapse of Open Hole Completion in Carbonate Formation

Abstract:

In TK oilfield, there is a large content of carbonatite in cambrian-ordovician, with great depth 4500m-6300m, high temperature 120oC -140oC, anisotropy, developed fracture system and complexity in geological structure. This paper is concerned about wellbore collapse in open hole completion of well R1 and other wells in the collepse well area, and trying to solve this problem through statistics of collapsed wells, and calculate with the mechanics model coupled with temperature field, fluid flow field and rock-mud physicochemical reactions. The result show that the development of hydration stress in planes of weakness, occurrence of nature fractures and technic stress are the most influential factors on wellbore stability. A wellbore in a formation with nature fractures around the wellbore has a testing pressure difference window of 21-28MPa.

• Periodical: Applied Mechanics and Materials (Volumes 220-223)
• Pages: 150-156
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.220-223.150
• Online since: November 2012
• Authors: Xiang Tong Yang, Zhi Yuan Liu, Hao Zhang, Qi Quan Xiong, Hong Tao Liu
• Keywords: Carbonate Formation, Nature Fracture, Testing Pressure Difference, Wellbore Collapse, Wellbore Stability

References

[1] Dinesh G, Musharraf Z. Stability of bore holes in a geologic medium including the effects of anisotropy [J]. Applied Mathematics and Mechanics, 1999, 52( 8) : 712-731.

[2] Y Jin, M Chen, G H Liu, et.al. Wellbore mechanics stability problem of directional well in weakly consolidated reservoirs [J]. Drilling & Product ion Technology, 1999, 23(4) : 33-35.

[3] F X Zhang, S L Zhang, X H Jiang, et.al. Borehole stability in naturally fractured reservoirs during production tests [J]. Petroleum Science,2008,11(5):247-250.

DOI: 10.1007/s12182-008-0039-8

[4] Yan Jin, Mian Chen, K.p. Chen. Pre-Caspian basin wells in salt-gypsum beds require an optimized drilling fluid. Oil & Gas J. 2010,108(4)：46-53.

[5] Weifen Gei, Mian Chen, Yan Jin. Analysis of the External Pressure on Casings Induced by Salt-Gypsum Creep in Build-up Sections for Horizontal Wells [J]. Rock Mech Rock Eng.

DOI: 10.1007/s00603-011-0162-5

[6] Aadony B S. Modeling of the stability of highly inclined boreholes in anisotropic rock formations[R]. SPE16526, 1988.

[7] Mian Chen, Yan Jin. Petroleum related rock mechanics[M]. Beijing: Science Press, 2008: 105.In Chinese.

[8] Yan Jin, Jianbo Yuan, Mian Chen, K.P. Chen, Yunhu Lu, Huaiying Wang. Determination of Rock Fracture Toughness KIIC and its Relationship with Tensile Strength Rock Mech Rock Eng(2011) 44:621–627.

DOI: 10.1007/s00603-011-0158-1

[9] Yan Jin, K. P Chen, M Chen, Development of tensile stress near a wellbore in high pressure gas flows[J]. International Journal of Rock Mechanics & Mining Sciences 48 (2011):1313–1319.

DOI: 10.1016/j.ijrmms.2011.09.013

[10] Yan Jin, Mian Chen, Kang Ping Chen, et.al. Short-time pressure response during the start-up of a constant-rate production of a high pressure gas well. Physics of Fluids, Volume 23, Issue 4, pp.043101-9 (2011).

DOI: 10.1063/1.3571494

[11] Kang Qiu, The Study of Collapse Mechanism of fractured sandstone reservoir in the Ultra-deep High Pressure Gas Well drilling Test[D], China University of Petroleum, Beijing,2011.In Chinese.

[12] Jaeger JC, Cook NGW, Zimmerman RW. Fundamentals of rock mechanics[M]. Oxford: Blackwell, 2007.

[13] Yan Jin, Zili Qi, Mian Chen, et.al. A mechanism study on the fractured reservoir instability during well testing of horizontal wells[J]. ACTA PETROLEI SINICA, 2011, (02): 295-298. In Chinese.

[14] Yan Jin, Zili Qi, Mian Chen. Time-sensitivity of the Kaiser effect of acoustic emission in limestone and its application to measurements of in-situ stress. Pet.Sci.(2009)6:176-180.

DOI: 10.1007/s12182-009-0028-6

[15] Yan Jin, Mian Chen, K.p. Chen. Depressant replaces mechanical method for removing blockage [J]. Oil & Gas. 2009,117(41).