摘要
天然气水合物多赋存在非成岩地层中,在开采过程中易出现出砂和沉降情况,制约了天然气水合物的安全高效长期开采。为研究水合物开采过程中的温压、产气、产水、出砂和沉降情况,在自主研发水合物出砂及防砂模拟装置上进行了不同条件下的开采模拟实验。研究表明,在前两个生产阶段,产水含砂率和出砂粒径随着水合物开采而逐渐增大;水合物细砂储层产气速率增加会增大携液能力,导致携砂能力增强而增大出砂风险,同时高产气速率促进井筒温度降低导致冰相生成,存在冰堵的风险;开采过程中的储层沉降与储层水合物含量相关性较大,而产气速率和降压速率对储层沉降的影响与产气模式有关。水合物开采中后期进行增产作业会增加储层出砂风险和沉降速率,进一步探讨了该实验对日本2013年第一次海域水合物试采出砂情况的推测,提出水合物开采分阶段分级防砂的概念。
Nature gas hydrate mainly exists in non-diagenetic strata, and sand production and reservoir subsidence often happen during mining, which restrict the safe and sustainable production of gas hydrate. In order to study the relationship of sand production and reservoir subsidence with temperature, pressure, gas production, water production of hydrate exploitation, simulation tests under different conditions were conducted with a self-developed device for sand production and sand control. It is observed that the sand ratio and grain size of water gradually increased in the first two production stages;For fine-grained sand reservoir, increasing the gas production rates will enhance the sand carrying ability of water, so that the sand production risk increases. At the same time, high-gas-production will accelerate the temperature decrease and lead to the formation of ice-phase,and/or ice blocking. The reservoir subsidence during hydrate exploitation is closely related to hydrate content in the reservoir. However, the influence of gas production rates and depressurization rates on reservoir subsidence are related to gas production mode. The stimulation operation in the mid-late stages of hydrate exploitation will increase sand production risk and subsidence. We further discussed the sand production taking the first marine hydrate mining case in Japan in 2013 and proposed the concept of sand prevention according to grades and stages.
作者
卢静生
熊友明
李栋梁
梁德青
金光荣
何勇
申小冬
LU Jingsheng;XIONG Youming;LI Dongliang;LIANG Deqing;JIN Guangrong;HE Yong;SHEN Xiaodong(State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China;Key Laboratory of Gas Hydrate, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China;State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China)
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2019年第4期183-195,共13页
Marine Geology & Quaternary Geology
基金
国家重点研发计划“南海多类型天然气水合物成藏原理与开采基础研究”(2017YFC0307305)
自然资源部海底矿产资源重点实验室开放基金“南海天然气水合物开采过程中的防砂研究”(KLMMR-2018-B-05)
广东省自然科学基金“海域天然气水合物开采出砂机理和防砂研究”(2017A030310448),“南海天然气水合物开采过程地层变形机制”(2018B0303110007)
广东省促进经济发展专项资金(海洋经济发展用途)“天然气水合物先导区建设与资源区块优选”(GDME-2018D001),“南海天然气水合物高效开采与控制技术研究”(GDME-2018D002)
国家自然科学基金项目“南海天然气水合物储层水合物开采过程地质力学参数演化规律研究”(51661165011)
关键词
非成岩水合物储层
降压开采
出砂实验
沉降
增产作业
non-diagenetic hydrate reservoir
depressurization exploitation
sand production experiments
subsidence
stimulation operation
