麻黄山区块深井钻井液技术

宁深1井是部署在麻黄山区块的一口区域深探井,该井设计井深5820m,采用三级井身结构。根据地质特征,认为该井钻井液主要技术难点为二开裸眼段长达3130m,井眼尺寸大,且地层破碎、倾角大,易发生垮塌及井漏,钻井液维护困难;山西组、太原组煤层较为发育,井壁容易失稳;预计井底温度高达185℃,高温对钻井液流变性、滤失量控制影响大。根据各开次的需求,室内形成配套钻井液体系,一开选用钾铵基聚合物钻井液体系;二开采用聚合物防塌及聚磺防塌钻井液体系;三开采用聚磺非渗透防塌钻井液体系。采用"多元协同"防塌技术解决井壁失稳,确保二开电测、下套管一次性成功,二开井径扩大率为13%,低于设计要求的20%。受二开套管事故的影响,三开施工井下情况复杂,及时调整钻井液性能,确保了该井的顺利完钻(完钻井深4756m)。在三开下部含多套煤层情况下,井径扩大率只有15.76%。采用非渗透处理剂进行随钻堵漏,可有效降低钻井液漏失。

Drilling Fluid Technology for Deep Wells in Mahuangshan Block

The well Ningshen 1 is a deep exploratory well with 5820m depth and three-order well profile,which deployed in Mahuangshan block.According to geologic characteristics,the major difficulty of drilling fluid is as follows: the fractured and high inclination formation is easy to collapse and loss,meanwhile it is difficult to maintain drilling fluid performance for the second spud with 3130m big size open hole;the developed coal layers in Shanxi group and Taiyuan group show wellbore instabilization;the expected...