滇西南钾盐调查MK-3大口径超深井绳索取心钻进工艺

Application of wireline core drilling technology in the large-diameter and ultra-deep potash survey well MK-3 in southwestern Yunnan

摘要:

滇西南中生代盐盆地钾盐资源调查评价项目MK-3井，设计井深2700 m，全孔取心，岩心直径≮80 mm，一般井段岩心采取率达到80%以上，盐岩段岩心采取率＞95%。工程技术要求高，施工难度大。施工中遇到了地层坍塌、涌水、掉块、盐岩溶蚀等问题，通过采用氯化镁饱和盐水冲洗液，HXY-9B型钻机取心钻进、TSJ-2000型水源钻机扩孔钻进，分级下管隔离等措施，圆满完成了钻探任务。完钻井深2701 m，岩心采取率90%，盐岩段岩心采取率达98.65%，终孔口径127 mm，岩心直径81 mm。经地球物理测井，各项指标都达到了设计要求。刷新了国内CHD127标准绳索取心钻杆P口径钻探深度的记录。

Abstract:

The MK-3 well was drilled for investigation and evaluation of potash resources in the Mesozoic salt basin in southwestern Yunnan with the design depth of 2700m, full hole coring and the core diameter not less than 80mm, the core recovery more than 80% over the non-ore bearing section, and more than 95% over the ore-bearing section. The technical requirements were demanding and it was difficult to drill. During drilling, problems such as stratum collapse, water gushing, stone falling and salt rock dissolution were encountered. The drilling task was successfully completed by adopting measures such as magnesium chloride saturated brine drilling fluid, coring with HXY-9B drilling rig, reaming with TSJ-2000 water well drilling rig, multiple tiers of casing for staged sealing off. The well was completed at depth of 2701m with average core recovery rate 90%, and 98.65% over the ore-bearing section. The final hole diameter was 127mm, and the core diameter was 81mm. Geophysical well logging indicated that each index has met the design requirement. It breaks the record of drilling depth by CHD127 standard wire coring drill pipe for “P size” in China.