渤南区块页岩油地层油基钻井液技术

渤南区块沙三储层以泥页岩为主，层理和微裂缝发育，采用常规水基钻井液水平钻进时，维持井壁稳定的难度很大。室内研究形成了柴油基钻井液和低芳烃油基钻井液配方，考察了其基本性能、封堵性能和抗原油污染性能。研制的柴油基钻井液在渤页平1井进行了现场应用，低芳烃油基钻井液在渤页平2井进行了现场应用。现场应用中未出现因钻井液导致的井下故障，起下钻通畅，无掉块，电测井段井径扩大率均小于3%。室内评价试验和现场应用表明，强封堵油基钻井液具有性能稳定、抑制性强、井壁稳定性好、润滑性强等特点，适用于泥页岩水平井钻井施工。 

Oil-Based Drilling Fluid Applied in Drilling Shale Oil Reservoirs in Bonan Block

Sha 3 Reservoir in Bonan Block is mainly shale with rich bedding and micro-fractures,it is difficult to maintain hole stability of horizontal well when drilling with conventional water-base drilling fluid.Diesel base drilling fluid system and low aromatic oil base drilling fluid system have been developed in laboratory,and their basic properties,fracture-blocking properties and anti-oil pollution performance were studied.Diesel base drilling fluid system developed was applied in Well Boye Ping 1,and low aromatic oil-based drilling fluid was applied at Well Boye Ping 2.The drilling of the two wells had no complex situations,smooth trips and no sloughing,the borehole enlargement rates were all less than 3%.Laboratory evaluation experiments and field application showed that strong blocking oil-base drilling fluid systems feature stable system,strong inhibition,good wellbore stability and strong lubricity,suitable for horizontal well drilling in shale formations.