Discover the SciOpen Platform and Achieve Your Research Goals with Ease.
Search articles, authors, keywords, DOl and etc.
Natural gas hydrates have significant economic and environmental potential, and their exploitation and utilization are of strategic significance for national energy security and realizing “dual carbon goals”of peak carbon and carbon neutrality. The majority of hydrates in China are distributed in the South China Sea. The complexity and concealment of the marine environment result in highly uncertainty of engineering measurement data, which affects drilling safety. However, there is a lack of reliability analysis for wellbore stability in hydrate reservoirs. Based on the analytical model of wellbore stability in hydrate reservoirs and the specific geological conditions of the Shenhu area in the South China Sea, the reliability analysis methods including the advanced first-order second-moment method and the response surface method are employed to quantitatively assess the probability of wellbore instability during drilling, and to analyze the sensitivity of the wellbore instability probability and safe drilling fluid pressure window to the mean and uncertainty of the main parameters. The research results indicate that: (1) If the measurement data are accurate enough, the drilling in hydrate reservoirs in the Shenhu area of the South China Sea is highly safe and the safe drilling fluid pressure window is also large. However, the increased uncertainty of measurement data can significantly increase the probability of wellbore instability and narrow the safe drilling fluid pressure window. (2) A lower drilling fluid temperature can slightly reduce the probability of wellbore instability and significantly increase the safe drilling fluid pressure window. (3) The mean and uncertainty of the five main parameters have the same order of influence on the probability of wellbore instability, that is: initial in situ stress > initial internal friction angle > elastic modulus ratio > initial cohesion > initial elastic modulus. Accurate measurement of initial in situ stress in practical engineering can significantly improve the wellbore stability in hydrate reservoirs.
YE Zhi-gang, WANG Lu-jun, ZHU Bin, et al. Thermo-hydro-mechanical coupling model for natural gas hydrate-bearing sediments with depressurization based on OpenGeoSys[J]. Rock and Soil Mechanics, 2023, 44(11): 3191−3202.
FU Qiang, ZHOU Shou-wei, LI Qing-ping. Natural gas hydrate exploration and production technology research status and development strategy[J]. Strategic Study of CAE, 2015, 17(9): 123−132.
WANG H N, CHEN X P, JIANG M J, et al. Analytical investigation of wellbore stability during drilling in marine methane hydrate-bearing sediments[J]. Journal of Natural Gas Science and Engineering, 2019, 68: 102885.
GUO Zhen-yu, WANG Hua-ning, JIANG Ming-jing. Elastoplastic analytical investigation of wellbore stability for drilling in methane hydrate-bearing sediments[J]. Journal of Natural Gas Science and Engineering, 2020, 79: 103344.
ROSHAN H, RAHMAN S S. The effect of water content on stress changes around a wellbore drilled in a chemically active elastoplastic formation[J]. Petroleum Science and Technology, 2013, 31(20): 2118−2126.
RAFIEEPOUR S, GHOTBI C, PISHVAIE M R. The effects of various parameters on wellbore stability during drilling through shale formations[J]. Petroleum Science and Technology, 2015, 33(12): 1275−1285.
SUN J X, NING F L, LEI H W, et al. Wellbore stability analysis during drilling through marine gas hydrate-bearing sediments in Shenhu area: a case study[J]. Journal of Petroleum Science and Engineering, 2018, 170: 345−367.
AL-AJMI A M, ZIMMERMAN R W. Stability analysis of vertical boreholes using the Mogi-Coulomb failure criterion[J]. International Journal of Rock Mechanics and Mining Sciences, 2006, 43(8): 1200−1211.
ZHANG Li-song, YAN Xiang-zhen, YANG Xiu-juan, et al. Elasto-plastic analysis of collapse pressure for deep coal seam drilling based on Hoek-Brown criterion[J]. Journal of China Coal Society, 2013, 38(1): 85−90.
MA T S, YANG Z X, CHEN P. Wellbore stability analysis of fractured formations based on Hoek-Brown failure criterion[J]. International Journal of Oil Gas and Coal Technology, 2018, 17(2): 143−71.
CHEN Ying-jie, DENG Chuan-guang, MA Tian-shou. A risk assessment method of wellbore instability based on the reliability theory[J]. Natural Gas Industry, 2019, 39(11): 97−104.
ZHANG Lu-lu, ZHANG Jie, XU Yao, et al. Reliability theory in geotechnical engineering[M]. Shanghai: Tongji University Press, 2011.
LÜ Q, LOW B K. Probabilistic analysis of underground rock excavations using response surface method and SORM[J]. Computers and Geotechnics, 2011, 38(8): 1008−1021.
MA T S, ZHANG Y, QIU Y, et al. Effect of parameter correlation on risk analysis of wellbore instability in deep igneous formations[J]. Journal of Petroleum Science and Engineering, 2022, 208 (Part C):109521.
YAO Yun-qi, ZENG Run-qiang, MA Jian-hua, et al. Reliability analysis of slope under rainfall infiltration considering preferential flow model[J]. Rock and Soil Mechanics, 2022, 43(8): 2305−2316.
SHENG Ya-nan, GUAN Zhi-chuan, LUO Ming, et al. Sensitivity analysis on the random variables of borehole stability reliability based on Monte-Carlo method[J]. Oil Drilling & Production Technology, 2018, 40(1): 14−19.
FARAVELLI L. A response surface for approach for reliability analysis[J]. Journal of Engineering Mechanics, 1989, 115(12): 2763−2781.
GAVIN H P, YAU S C. High-order limit state functions in the response surface method for structural reliability analysis[J]. Structural Safety, 2008, 30(2): 162−179.
MYERS R H, MONTGOMERY D C. Response surface methodology: process and product optimization using designed experiments[M]. New York: John Wiley & Sons, 1995.
OU Fen-lan, YU Yan-jiang, KOU Bei-bei, et al. Gas hydrate reservoir types, characteristics and development methods[J]. Marine Geology & Quaternary Geology, 2022, 42(1): 194−213.
MORIDIS G J. Numerical studies of gas production from methane hydrates[J]. SPE Journal, 2002, 8(4): 359−370.
AADNØY B S, BELAYNEH M. Elasto-plastic fracturing model for wellbore stability using non-penetrating fluids[J]. Journal of Petroleum Science and Engineering, 2004, 45(3−4): 179−192.
GOEL N, WIGGINS M, SHAH S. Analytical modeling of gas recovery from in situ hydrates dissociation[J]. Journal of Petroleum Science and Engineering, 2001, 29(2): 115−127.
JI C, AHMADI G, SMITH D H. Natural gas production from hydrate decomposition by depressurization[J]. Chemical Engineering Science, 2001, 56(20): 5801−5814.
HONG H, POOLADI-DARVISH M, BISHNOI P R. Analytical modelling of gas production from hydrates in porous media[J]. Journal of Canadian Petroleum Technology, 2003, 42(11): 45−56.
HUANG J J, JIANG M J, WANG H N. An analytical model of time-dependent elastoplasticity with hydraulic–mechanical coupling for wellbore stability in hydrate exploitation[J]. Marine Georesources & Geotechnology, 2023, 41(12): 1354−1369
COUSSY O. A general theory of thermoporo-elastoplasticity for saturated porous materials[J]. Transport in Porous Media, 1989, 4(3): 281.
WU B, XI Z, JEFFREY R G, et al. A semi-analytic solution of a wellbore in a non-isothermal low-permeability porous medium under non-hydrostatic stresses[J]. International Journal of Solids and Structures, 2012, 49(13): 1472.
GASSMANN F. Elastic waves through a peaking of spheres[J]. Geophysics, 1951, 16(4): 673−685.
ZHAO L, CAO C, YAO Q, et al. Gassmann consistency for different inclusion-based effective medium theories: implications for elastic interactions and poroelasticity[J]. Journal of Geophysical Research: Solid Earth, 2020, 125(3): e2019JB018328.
YANG Shi-ming, TAO Wen-shuan. Heat transfer (second edition)[M]. Beijing: Higher Education Press, 2006.
DICKENS G R, QUINBY-HUNT M S. Methane hydrate stability in seawater[J]. Geophysical Research Letters, 1994, 21(19): 2115−2118.
ZHANG Ming, JIN Feng. Structural reliability computations[M]. Beijing: Science Press, 2015.
ZHANG W, LIANG J Q, WEI J G, et al. Origin of natural gases and associated gas hydrates in the Shenhu area, northern South China Sea: results from the China gas hydrate drilling expeditions[J]. Journal of Asian Earth Sciences, 2019, 183: 103953.
WU N Y, ZHANG H Q, YANG S X, et al. Gas hydrate system of Shenhu area, Northern South China Sea: geochemical results[J]. Journal of Geological Research, 2011. DOI: 10.1155/2011/370298.
LI J F, YE J L, QIN X W, et al. The first offshore natural gas hydrate production test in South China Sea[J]. China Geology, 2018, 1(1): 5−16.
YE J L, QIN X W, XIE W W, et al. The second natural gas hydrate production test in the South China Sea[J]. China Geology, 2020, 3(2): 197−209.
YE Jian-liang, QIN Xu-wen, XIE Wen-wei, et al. Main progress of the second gas hydrate trial production in the South China Sea[J]. China Geology, 2020, 47(3): 557−568.
MASUDA Y, NAGANAWA S, ANDO Y, et al. Numerical calculation of gas-production performance from reservoirs containing natural gas hydrates[J]. SPE Journal, 1997, 29(3): 201−210.
ZHU Xiao-hua, SUN Han-wen, ZHAO Jin-zhou, et al. Damage constitutive model of equivalent variable elastic modulus for gas hydrate sediment[J]. Acta Petrolei Sinica, 2019, 40(9): 1085−1094.
DONG Lin, LIAO Hua-lin, LI Yan-long, et al. Measurement and assessment of mechanical properties of hydrate-bearing sediments[J]. Marine Geology Frontiers, 2020, 36(9): 34−43.
YONEDA J, MASUI A, KONNO Y, et al. Mechanical properties of hydrate-bearing turbidite reservoir in the first gas production test site of the Eastern Nankai Trough[J]. Marine and Petroleum Geology, 2014, 66: 471−486.
SUN J X, ZHANG L, NING F L, et al. Production potential and stability of hydrate-bearing sediments at the site GMGS3-W19 in the South China Sea: a preliminary feasibility study[J]. Marine and Petroleum Geology, 2017, 86: 447−473.
MA Tian-shou, ZHANG Yun, QIU Yi, et al. Risk evaluation method of borehole instability of deviated wells based on reliability theory[J]. Acta Petrolei Sinica, 2021, 42(11): 1486−1498.
MA T S, TANG T, CHEN P, et al. Uncertainty evaluation of safe mud weight window utilizing the reliability assessment method[J]. Energies, 2019, 12: 942.
LIU Dong-sheng, ZHANG Lang, LIU Shan-wen, et al. Analytical expression of yield probability on Mohr-Coulomb criterion[J]. Chinese Journal of Underground Space and Engineering, 2008, 4(2): 238−242.