四川盆地天然气钻前工程选址风险识别与防控措施

Risk identification and prevention measures for pre-drilling site selection in the Sichuan Basin

四川盆地油气探区人口稠密、河流密布、植被茂盛、环境敏感、地质构造复杂,属地质灾害易发区,钻前工程选址风险因素较多,风险较大。为了防灾减灾,有效降低钻前工程风险,从管理和技术的角度出发,对四川盆地油气探区滑坡、泥石流、岩石崩塌地质灾害、环境危害、洪水灾害、矿井(坑道)、溶洞危害及工程实施本身等各类风险进行了分类识别,并从钻前工程选址应遵循的原则、开展环境和地质灾害评估、调查走访、地质勘查、控制安全距离、主动避让等方面提出了预防和控制的措施。结论认为,通过充分识别、诊断并采取以规避为主、处治为辅的防控措施,可以规避和降低钻前工程选址风险,保障四川油气田勘探开发的顺利实施,也对其他类似山地油气勘探的钻前工程选址具有一定的借鉴意义。

The pre-drilling site selection is always challenged by high risks due to many factors in the hydrocarbon exploration zones in the Sichuan Basin,where,despite a dense population,there are many rivers,flourishing plants and trees.Besides,this area with environmental sensitivity is subject to geological hazards and the geological structures of formations are quite complex.In view of this,risks are identified and classified into different types: geological hazards like landslide,debris flow,eboulement,etc.,natural disasters like floods,environmental hazards,harms from mine tunnels or karst caves,and potential threats in the engineering,and so forth.On this basis,some risk prevention and control measures are put forward for the pre-drilling site selection in the following aspects: the principles to be followed,evaluation to be made on the environmental and geological hazards,safety distance to control,action to avoid any potential dangers,as well as investigation and extensive visits,geological survey,etc.In conclusion,the risks in pre-drilling site selection in the Sichuan Basin can be avoided in the first place as long as being identified and prevented by effective countermeasures,thereby to ensure the smooth operation of exploration and development in the Sichuan oil and gas fields and to provide reference for the pre-drilling site selection in other similar areas.