南海西部深水高温高压钻井液技术研究与应用

Research and applications of deep water HTHP drilling fluid in western South China Sea

南海西部陵水区块高温高压引起深水钻井作业窗口进一步变窄,高温与低温并存使钻井液性能难以维护。在常规深水钻井液HEM体系的基础上,通过优选抗低温水合物抑制剂和抗高温降失水剂构建了南海西部深水高温高压钻井液体系。室内评价表明,所构建的钻井液体系具有良好的低温—高温流变性、抗污染能力、沉降稳定性、封堵承压性、储层保护性、泥页岩水化抑制性。该钻井液体系已在南海西部陵水区块3口深水高温高压井取得成功应用,可避免井漏、溢流等复杂情况,提高了作业效率,具有良好的推广应用价值。

The characteristic of HTHP in western South China Sea leads to a narrower operation window, which brings difficulties to drilling fluid property maintenance under coexistence of low and high tempera- tures. A deep water HTHP drilling fluid system for western South China Sea is formulated on the basis of traditional HEM drilling fluid by screening low temperature hydrate inhibitors and high temperature fil- trate reducers. Lab experiments show that the novel deep water HTHP drilling fluid system possesses sound rheology at both low and high temperatures, contamination tolerance, suspension-stability, as well as good fissure-sealing, reservoir protection and shale inhibiting capabilities. It has been successfully ap- plied recently in three deep water HTHP wells in Lingshui Block of western South China Sea. This drilling fluid system boosts operation efficiency by greatly reducing downhole complexes such as lost circulation and kick. Hence, it can serve as a technical reference for future deep water HTHP operations.