塔深1井奥陶系堵漏及微漏强钻工艺技术

Mud Losses Control technology in Well Tashen-1

塔深1井完钻井深为8408m。该井钻至井深6237m，发生有进无出的恶性漏失，此时钻遇地层为奥陶系鹰山组，地层层理发育、破碎，属共存裂缝和溶洞型、压力敏感型漏失地层。由钻时分析结果和成像测井结果可知，该井严重漏失层段为6237-6278m，其中有十几米（不等厚互层）达放空状况。由于参考资料太少，造成对漏层性质、敏感性、缝洞宽度的分析不准确，结果堵漏6次才制定出有效的堵漏配方。第9次堵采用桥塞堵漏技术，使漏速降至3～6m^3／h，随后在微漏条件下实施强钻工艺措施，安全顺利钻达四开井深（6800m），最后顺利下入套管并成功固井。

Well Tashen-1 is a deep well having a depth of 8408 m.At a depth of 6237 m(Yingshan Formation of Ordovician system) mud losses with no return were encountered.It was reported that the formations,which were bedded formations,have very developed fractures and even vugs,into which mud were lost.Analyses of the logging data showed that mud losses in this well occurred at depths between 6237-6278 m,in which loss of bit load with loss return took place in more than ten meters(interbeds of unequal thickness).Six times of trying to resume circulation were failed because of the lack of detailed data.Finally use bridging-plugging technology to reduce the rate of loss to 3-6 m3/h.After that the well was drilled while the mud was lost at acceptable lower rates and was cased successfully.