摘要
碳酸盐岩地层连通性较好,多发育裂缝溶洞型地层,经常发生重力置换式溢流,溢流与漏失并存,难以处理.在一些区块中,由于油与油基钻井液发生重力置换溢流,常导致钻井液密度降低,无法平衡井底压力,造成恶性溢流事故.为了及时处理溢流事故,实现安全钻井,需要掌握油与油基钻井液发生地层重力置换的机理,从理论出发指导现场处理重力置换溢流.因此,基于自主研制的井筒-裂缝-地层重力置换实验装置,开展重力置换实验,证明了重力置换现象的存在;配置油基钻井液,开展油基钻井液与油重力置换实验,发现由于地层原油与油基钻井液发生反应,会导致油基钻井液密度与粘度明显下降,导致油基钻井液无法平衡井底压力,影响钻井进程,实验对现场处理重力置换溢流具有指导意义.
Abstract
Carbonate rock formation has good connectivity,more developed cracks and karst cave for-mation,gravity displacement overflow often occurs,overflow and leakage coexist,it is difficult to deal with.In some blocks,the gravity displacement overflow of oil and oil-based drilling fluid often leads to the reduction of drilling fluid density,which cannot balance the bottom pressure,resulting in malignant o-verflow accidents.In order to deal with overflow accidents in time and realize safe drilling,it is necessary to master the mechanism of formation gravity replacement between oil and oil-based drilling fluid,and guide the site to handle gravity displacement overflow from the theory.Therefore,based on the self-de-veloped gravity displacement experiment of the wellbore-fracture-formation gravity displacement exper-imental device,and the oil-based drilling fluid cannot balance the oil-based drilling fluid,it is found to affect the drilling process,the experiment has guiding significance for the treatment of gravity displacement overflow.
基金项目
中石化胜利钻井院研究项目(1020001-22-ZC0613-0044)
NETL
NSTL
万方数据