中国石油大学学报（自然科学版）Issue(1)：103-110,8.DOI:10.3969/j.issn.1673-5005.2015.01.015
缝洞型油藏溶洞临界垮塌深度预测模型及其应用
A prediction model for collapse of karst caves in fractured-vuggy oil reservoirs and its application
摘要
Abstract
The karstic caves in fractured-vuggy oil reservoirs may collapse during drilling. A model was proposed to predict the critical burial depth of the caves, which may cause cave collapse during well-drilling operations. The model was based on a method of depth dichotomy reduction and the data from the fractured-vuggy reservoirs in Tahe Oilfield Northwest China were used. Various factors that may affect the collapse of the cave were analyzed. A correlation for predicting the critical collapse depth was given through a multivariate regression analysis method, considering the influence of the coping thickness and span of the caves, and the lateral pressure coefficient. A case study for different caves in Tahe Oilfield was conducted. The analysis re-sults show that the collapse of rectangle and horseshoe-shaped caves can be attributed to vertical shear failure, while the col-lapse of circular caves can be due to compaction failure. The influence area of the collapse increases with cave°s coping thick-ness and span, the largest influence area can be extended to 2. 6 times of the cave span, which is the most sensitive factor to cave collapse. The lateral pressure coefficient is a less sensitive factor in comparison with the cave°s coping thickness and span. The circular caves are more stable than the horseshoe-shaped caves, and the rectangle caves are most vulnerable for collapse. The predicted results agree well with oilfield data.关键词
缝洞型油藏/临界垮塌深度/二分深度折减法/溶洞垮塌模式/垮塌深度预测模型Key words
fracture-vuggy oil reservoir/critical collapse depth/method of depth dichotomy reduction/cave collapse mode/collapse depth prediction model分类
能源科技引用本文复制引用
王超,张强勇,刘中春,袁圣渤,张绪涛,王有法..缝洞型油藏溶洞临界垮塌深度预测模型及其应用[J].中国石油大学学报（自然科学版）,2015,(1):103-110,8.基金项目
国家自然科学基金项目(41172268,51279093) （41172268,51279093）
国家科技重大专项(2011ZX05014) （2011ZX05014）
