古龙页岩油双节密闭取芯技术研究与应用  

Research and Application of Double Section Closed Coring Technology for Gulong Shale Oil

作　　者：田佳琦 张洪君[1] 向峰[1] 张绍先 TIAN Jia-qi;ZHANG Hong-jun;XIANG Feng;ZHANG Shao-xian(Daqing Drilling Engineering Company Drilling Engineering Technology Research Institute,Daqing Heilongjiang 163413,China)

机构地区：[1]大庆钻探工程公司钻井工程技术研究院,黑龙江大庆163413

出　　处：《西部探矿工程》2023年第12期22-25,30,共5页West-China Exploration Engineering

摘　　要：密闭取芯技术是指在水基钻井液的条件下,采用密闭取芯工具和密闭液,获取几乎不受钻井液污染岩芯的取芯技术,从而获得更加准确的含油饱和度,为计算油田储量、制定合理的开发方案提供可靠的地质依据,也是检查和评价油田开发效果最主要的技术手段。而目前的密闭取芯工具最大可取岩芯长度9.5m,面对青山口组地层井壁不稳定、取芯钻头易泥包、起下钻次数多等技术难题,单筒密闭取芯效率低,取芯周期长,超过井壁坍塌周期会引起井下复杂情况发生,为了提高页岩油密闭取芯效率和取芯机械钻速,研制了双节密闭取芯工具和8刀翼取芯钻头,优化了双节密闭取芯工具双筒单动、内筒扶正、泄压机构和出芯工艺,首次实现了双节密闭取芯技术,采用的耐高温、流动性好、密闭能力强的油基密闭液,提高了岩芯密闭效果。该技术应用1口密闭取芯井(井号:古页8HC),共取芯8筒,总进尺128.72m,总芯长127.68m,岩芯收获率99.19%,平均单趟进尺16.09m,平均钻速4.51m/h;应用3口常规取芯井,共取芯30筒,总进尺482.4m,总芯长478.92m,平均岩芯收获率99.28%,平均单趟进尺16.08m,在页岩油取芯中提速提效明显,该技术填补了油田内双节密闭取芯技术空白。Closed coring technology refers to the use of sealed coring tools and fluids under the conditions of water-based drilling fluids to obtain cores that are almost free from drilling fluid contamination,thereby obtaining more accurate oil saturation.It provides reliable geological basis for calculating oilfield reserves and formulating reasonable development plans,and is also the most important technical means to check and evaluate the effectiveness of oilfield development.At present,the maximum allowable core length for sealed coring tools is 9.5 meters.In the face of technical difficulties such as unstable wellbore in the Qingshankou Formation,easy mud entrapment of coring bits,and multiple trips,the efficiency of single barrel sealed coring is low,and the coring cycle is long.Exceeding the wellbore collapse cycle can cause downhole complications.In order to improve the efficiency of shale oil sealed coring and the drilling speed of coring machinery,a double section sealed coring tool and an 8-blade coring bit have been developed.We have optimized the dual section sealed coring tool,dual cylinder single action,inner cylinder centering,pressure relief mechanism,and coring process,and achieved the dual section sealed coring technology for the first time.We use an oil-based sealing fluid with high temperature resistance,good flowability,and strong sealing ability,which improves the sealing effect of the core.This technology applies one sealed coring well(well number:Gu Ye 8HC),with a total of 8 cores taken,a total footage of 128.72 meters,a total core length of 127.68 meters,a core recovery rate of 99.19%,an average single run footage of 16.09 meters,and an average drilling speed of 4.51 m/h.Three conventional coring wells were applied,with a total of 30 cores taken,a total footage of 482.4 meters,a total core length of 478.92 meters,an average core recovery rate of 99.28%,and an average single run footage of 16.08 meters.This technology has significantly improved the speed and efficiency of shale oil coring,filling

关 键 词：双节密闭取芯 页岩油 取芯工具 古页8HC 

分 类 号：TE244[石油与天然气工程—油气井工程]