海底天然气水合物复杂地层钻进取芯仿真岩芯扰动分析  

Simulation Core Disturbance Analysis of Core Drilling in Complex Submarine Gas Hydrate Formation

作　　者：卫成效 金永平 刘德顺 万步炎 WEI Chengxiao;JIN Yongping;LIU Deshun;WAN Buyan(National-Local Joint Engineering Laboratory of Marine Mineral Resources Exploration Equipment and Safety Technology,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]湖南科技大学海洋矿产资源探采装备与安全技术国家地方联合工程实验室,湖南湘潭411201

出　　处：《湖南科技大学学报（自然科学版）》2023年第1期43-49,共7页Journal of Hunan University of Science And Technology：Natural Science Edition

基　　金：国家自然科学基金资助项目(51779092);国家重点研发计划项目资助(2016YFC0300502);湖南省研究生科研创新项目资助(CX20210985);湖南创新型省份建设专项经费资助项目(2020GK1021,2019SK2271,2019GK1010,2019GK1012)。

摘　　要：针对海底天然气水合物赋存的复杂地层,利用有限元分析软件ABAQUS/CAE,对搭载于深海海底钻机上的金刚石钻头钻进取芯海底天然气水合物过程进行了模拟仿真,并利用Python对仿真结果进一步处理.通过对钻进过程中岩芯所受应力状态的分析,得到岩芯扰动状态随钻进参数的变化规律,获得天然气水合物储层及其上覆土层沉积物低扰动岩芯范围,以及岩芯扰动率随钻进参数的变化趋势,对获取低扰动岩芯钻进参数及其优化具有一定的参考意义.结果表明:随着钻压和转速的增加,沉积物及水合物岩芯的扰动范围都相应的增大.岩芯的扰动率呈现出先迅速增大,之后再逐渐保持稳定的趋势.扰动率稳定值的大小受钻压的影响较大,与钻头的转速无关.当在沉积层钻进时,选择较大的钻压及转速以保证高的进尺效率,而当在水合物层钻进时,适当降低钻压可以获得质量较好的岩芯,而增大转速会使进尺速度得到有效的提升.Aiming at the complex formation for gas hydrate occurrence in seabed,this paper uses the finite element analysis software ABAQUS/CAE to simulate the drilling process of diamond bit mounted on deep seabed drilling rig for coring seabed gas hydrate.With further processing of simulation results using Python,this paper also analyzes the stress state of rock core during drilling,and the variation law of rock core disturbance state with drilling parameters is obtained.It obtains the low-disturbance core range of natural gas hydrate reservoir and its overlying sediments,and the variation trend of core disturbance rate with drlling parameters.It has certain referential significance for optimizing core drilling parameters with low disturbance.The results show that the disturbance range of sediments and hydrate cores increases with the increase of drilling pressure and rotational speed.The disturbance rate of the core first increases rapidly,and then gradually remains stable.The stability value of the disturbance rate is greatly affected by the drilling pressure,and has nothing to do with the speed of the bit.When drilling in the sedimentary layer,larger drilling pressure and speed should be selected to ensure high footage efficiency.When drlling in hydrate layer,the core with good quality can be obtained by appropriately reducing the drilling pressure,and increasing the rotational speed can effectively improve the footage speed.

关 键 词：天然气水合物 有限元分析 应力状态 岩芯扰动 

分 类 号：TE52[石油与天然气工程—油气田开发工程]