C101井钻井液技术

Drilling fluid technology of well C101.

C10 1井位于酒东盆地营尔凹陷 ,是一口深探井 ,完钻井深为 4 70 0m ,钻井周期为 2 36d。营尔凹陷地质构造复杂 ,自上而下有大砾石层、强造浆软泥岩层、芒硝层、石膏层和高压盐水层 ,极易造成井壁坍塌 ,给钻井施工增加了难度。针对不同的井段采用了不同的钻井液体系 :0～ 80 0m井段 (砾石层 )使用“三高一适当” ,即高膨润土含量、高粘度和高切力、高滤失量、适当密度的钻井液 ;80 0～ 32 0 0m井段 (棕红色软泥岩层 )使用复合金属两性离子聚合物钻井液 ;32 0 0～ 4 16 2m井段使用甲基硅油聚磺高密度钻井液 ;4 16 2～ 4 70 0m井段使用金属复合离子聚磺钻井液。在 32 0 0～4 16 2m井段采用了一些新的工艺技术 ,有效地保护了长裸眼井壁的稳定和高温高压下钻井液性能的稳定。应用结果表明 ,该套体系满足了C10 1井地层情况 ,全井无事故 ,复杂率为 1.2 9% (邻井事故率为 5 .0 2 % ,复杂率为 7.4 1% ) ,电测成功率为 10 0 % ,钻井周期比邻井缩短近 10 0d。

Well C101 is a deep exploration well located in Yinger sag of Jiudong basin. Its total depth is 4700 m and the drilling cycle is 236 days. The geologic structure is very complex, with large gravel bed,high mud making soft shale, chuco, gypsolyte and high pressured saltwater layer from top to bottom, andhole collapse is easy to occur. Different drilling fluids were used for different intervals: 1) In the gravel bed (0～800 m), a fluid called 'three high and one proper' drilling fluid which has high bentonite content,high viscosity and high shearing force, high filtration and proper density was employed; 2) During the or-ange soft shale (800～1463 m), a composite metal zwitterionic polymer drilling fluid was used; 3) In the 3200～4162 m section, a methyl silicone oil polysulfonate drilling fluid with high density was used. Several other new technologies were also applied to effectively ensure stability of both long open hole and drilling fluid under HTHP condition. Field using revealed that all drilling fluids had satisfied their interval drilling requirements with no problems happening. The complexity rate was 1.29%, (the failure rate was 5.02% and the complexity rate was 7.41% in offset wells), and the drilling cycle is shorted by 100 days compared With offset wells.