摘要
Abstract
The development of geothermal resources in Xiong'an New Area faces multiple drilling technology challenges,mainly reflected in the dual pressure of complex geological conditions and environmental protection.Deep geothermal reservoirs generally have high-temperature.The high downhole temperature makes it difficult to regulate the performance of the drilling fluid.In the fractured carbonate reservoirs,downhole complex situations such as lost circulation and wellbore collapse are likely to occur.Even irreversible lost circulation and pipe sticking accidents may occur,which seriously affect the drilling coring and mud logging operations.The rocks in the target reservoir are characterized by high hardness and strong abrasiveness,which seriously affect the rate of penetration.In response to the complex geological conditions of the karst geothermal reservoirs in the Xiong'an New Area,detailed geological research has been carried out,and the wellbore structure design has been optimized,mainly focusing on the three-section wellbore structure.In the face of the high-temperature environment,high-temperature-resistant positive displacement motors are used in combination with a high-temperature-resistant drilling fluid system.For the fractured non-target reservoirs,the lost circulation control technology while drilling is adopted,and nano-blocking materials and fiber-reinforced lost circulation materials are used in supporting.When drilling in the target layer of the karst geothermal reservoir,technologies such as clear water drilling,clear water with air injection drilling,and double-wall drill pipe drilling are adopted to solve the problem of formation lost circulation.In terms of environmental protection,the key work is to carry out harmless treatment of the waste drilling fluid,and a closed-circuit circulation system is applied to reduce the discharge of waste.关键词
岩溶热储/地热钻井/失返性漏失/卡钻事故/雄安新区Key words
karst heat reservoir/geothermal drilling/lost circulation/sticking accident/Xiong'an New Area分类
能源科技
