【摘要】：基于塔中11井區(qū)志留系砂巖易水鎖傷害、地層壓力系數(shù)低等鉆井儲層保護的難點,通過國內(nèi)外低壓油氣藏保護的鉆井液體系調(diào)研,認識到使用低密度全油基鉆井液是一種比較經(jīng)濟可行的保護措施。通過低密度全油基鉆井液的單劑合成和篩選,完成了低密度全油基鉆井液的體系構(gòu)建。構(gòu)建了以柴油為基液的低密度全油基鉆井液。實現(xiàn)了低密度全油基鉆井液的密度低至0.90g/cm3,抗溫能力達120℃～150℃,抗鉆屑和水污染10%～20%,滾動回收率達到95%以上,巖心滲透率恢復值達90%以上的良好效果。研制的低密度油基鉆井液在塔中11井區(qū)1口直井和1口水平井井應用,實現(xiàn)了微欠平衡或平衡鉆井,減少了壓持效應和井底壓差,提高了機械鉆速,同時減少了鉆井液中的固相向地層的侵入量；縮短了鉆井液浸泡時間,在高溫高壓下濾失量低,減小了鉆井液污染半徑；從本質(zhì)上降低了水鎖傷害。低密度全油基鉆井液在塔中應用情況表明,低密度全油基鉆井液具有性能穩(wěn)定、維護簡單、機械鉆速快等特點,各項性能滿足了鉆井液設計性能和儲層保護功能。通過油基鉆井液回收和重復利用,節(jié)約了鉆井成本,也減少了環(huán)境污染。低密度全油基鉆井液的儲層保護效果在于完井測試表皮系數(shù)0；巖心靜態(tài)滲透率恢復值90%,動態(tài)滲透率恢復值75%；其120-C失水8m1,兩口井完井試油產(chǎn)量都超過相應鄰井產(chǎn)量。
[Abstract]:Based on the difficulties of reservoir protection for Silurian sandstone in Tazhong 11 well area, such as easy water lock damage and low formation pressure coefficient, the drilling fluid system of low pressure reservoir protection at home and abroad is investigated. It is recognized that the use of low density oil-based drilling fluid is an economical and feasible protection measure. The system of low density whole oil based drilling fluid was constructed by single agent synthesis and screening of low density oil based drilling fluid. A low density oil-based drilling fluid based on diesel oil was constructed. The low density oil based drilling fluid has a low density of 0.90 g / cm ~ 3, a temperature resistance of 120 鈩，

本文編號：2356823