丘东27井长封固段固井实践

LONG ISOLATION INTERVAL CEMENTING PRACTICE IN WELL QIUDONG-27

钟福海 王维清 杨声贵 张伟 梁鹏飞 刘联军

Zhong Fuhai Wang Weiqing Yang Shenggui Zhang Wei Liang Pengfei Liu Lianjun

华北石油管理局固井工程处, 河北任丘 062552 长庆石油勘探局工程技术研究院, 陕西西安 710021

现场固井施工中,一般水泥封固段长800~1200m,而丘东27井由于构造断层多,地下情况复杂,要求一次水泥封固段长达3125m,这在以往的固井施工中极为罕见。由于长封固段固井时,井底流动温度与水泥浆返回处的静止温度差异较大,会造成水泥面处的水泥浆凝固不好,甚至长期不凝固,严重影响固井质量;长封固段固井将会大幅度地增加井底液柱压力,固井时极有可能发生漏失。通过大量室内试验,采用2种水泥浆体系进行固井,上部井段采用适用温度范围宽的低密度矿渣浆体系,下部井段采用常规密度水泥浆体系,并辅以适当的固井施工措施,克服气候极冷等诸多困难,固井一次成功,固井质量优质,为同类油井的固井提供了经验。

Cementing isolation interval usually ranges between 800~1200m,while in Well Qiudong-27,3125m long of isolation interval is required due to faulted structure and complex downhole conditions,which makes the operation extremely difficult.For long isolation cementing,due to the large temperature difference between the downhole flowing temperature and the static temperature at the cement top,poor cementation will be caused,and this severely affected the cementing quality;at the same time,long isolation cementing will also increase the bottomhole hydraulic pressure remarkably,thus cause lost circulation during cementing.Large scale of laboratory tests were conducted,and 2 types of cement slurry systems were selected for cementing;specifically,light weight slag slurry of wide temperature range was selected for the upper interval,while conventional cement slurry was used for the lower interval,and proper cementing measures were adopted.The cementing job for this well was successful,and excellent cementing quality was achieved.

10.3969/j.issn.1000-7393.2003.06.006