黄桥二氧化碳气田开发井钻井工艺

黄桥二氧化碳气田在钻井过程中存在直井段易井斜,浦口组地层缩径、垮塌及卡钻,下部地层先漏后涌等井下复杂情况或事故,及机械钻速低与钻具和套管腐蚀的问题。华泰2井和华泰3井在钻井过程中,通过不同井段选用不同钻头,采用不同钻具组合和钻井参数,解决了直井段易井斜的问题,提高了机械钻速;浦口组以上地层采用金属两性离子聚合物钻井液钻进,中生界以下地层使用金属两性离子聚合物防塌钻井液钻进,解决了浦口组地层缩径、垮塌和卡钻,及下部地层先漏后涌等问题;在钻遇二氧化碳气层后采取加入防腐处理剂等防腐措施,解决了钻具的腐蚀问题;通过室内管材动静态腐蚀评价试验,确定采用含Cr套管与普通套管相结合的套管完井方式,解决了套管腐蚀问题;采用微硅低密度水泥浆和胶乳不渗透防气窜水泥浆体系固井,提高了固井质量,有效防止了环空气窜。通过华泰2井和华泰3井2口井的钻井,形成了一套适合黄桥二氧化碳气田开发井的钻井工艺技术,为今后二氧化碳气田的开发提供了借鉴。

Drilling Techniques in Huangqiao CO2 Gas Field

A series of technical challenges exist during drilling the Huangqiao CO2 gas field,including hole deviation in vertical section,tight hole in Pukou formation,sloughing and pipe sticking,formation fluid influx after circulation loss in bottom formations,low drilling speed,drill string and casing string corrosion,etc.Wellbore deviation was solved by using different bottom hole assembly,drilling parameters and various bits in wells Huatai-2 and Huatai-3.A polymer drilling fluids with hybrid ions used in formations above Pukou section and an anti-sloughing polymer mud used in formations below the Mesozoic solved the problems,including tight hole,sloughing and pipe sticking in Pukou section,formation fluids overflow in lower formation.Drill string corrosion was solved by adding corrosion-resistant agents into the drilling fluid when drilling the CO2 gas formation.Based on dynamic and static lab tests,the casing string corrosion problem was solved by using the combination of casing strings with Cr and normal casing string for well completion.The cement quality was improved and gas channeling was prevented effectively by using cement slurry with low silicon content and low density and low permeability.Through the application on wells Huatai-2 and Huatai-3,a series of drilling techniques fit for Huangqiao CO2 gas field was established,which provides valuable references to recovering similar reservoirs in the future.