高压注水井套管缩径变形机理及防治技术——以史深100断块为例

高压注水井经过4年注水后套管疲劳损坏是低渗油藏开发过程中普遍存在的问题。通过对史深100断块现场调查分析,找出了高压注水井套管损坏的基本规律,主要受地质因素和钻井因素的影响,套损点主要集中在射孔部位附近的泥岩夹层及射孔井段。重点对以上两个部位高压注水时套管损坏的机理进行了研究,进行了现场分析,并匹配了相应的防治技术:完井时采用C—90钢级、壁厚10.54 mm套管;通过转注、防硼预处理、酸化解堵等措施控制注入压力过高等。现场应用取得了较好的效果,通过几年的综合防治,史深100断块水井套损率由2000年的10.0%下降到2005年的3.3%。

Casing damage mechanism and prevention-cure technique in high pressure injecting wells taking Shishen 100 oilfield as an example

The common problem existed in low permeability development is casing damage in high pressure injecting wells. Through on-site investigation and analysis in Shishen 100 oilfield, the basic rule of casing damage in high pressure injecting wells was discovered. The mainly factors are the influence of geology and well drilling, the casing damage mainly exists in clay rock interlayer nearby perforation and the perforation segment. The casing damage mechanism caused by these two above positions of high pressure injecting wells is studied emphatically and carry out in situ analysis. C-90 steel and casing pipe of 10.54mm were used when the high pressure injecting wells is finished and the high pressure was controlled by conversion,anti-boron pretreatment and acidification break-down technology. Field application has gotten better effect. Through the comprehensive prevention in recent years, the damage rate of high pressure injecting wells casing in Shishen 100 oilfield has decreased form 10.0 % in 2000 to 3.3 % in 2005.