Abstract
Cave collapses emerge during the process of oil reservoir development, seriously affecting oil production. To reveal the collapse and failure mechanism of the carbonate cavern with a buried depth of 5600 m in Tahe Oil Field, using a self-developed ultra-high pressure model test system with the intelligent numerical control function, the model simulation material of carbonate rocks developed to carry out the 3D geo-mechanical model test. The model test and numerical results indicate that: (1) collapse and failure mechanism of the deep-buried caves mainly involve the failure mode of tensile shear. The rupture plane on the side wall is approximately parallel to the direction of maximum principal compressive stress. The V-type tension and split rupture plane then emerges. (2) In the process of forming holes in the model caverns, micro cracks are generated at the foot of the left and right side walls of the caverns, and the roof panels are constantly moving downward. The shorter the distance to the cave wall, the severer the destructiveness of the surrounding rocks will be. (3) The displacement of the top of the model cavern is relatively large and uniform, indicating that the cave roof moves downward as a whole. The area of the cavity suffering damage is 2.3 times as large as the cave span. The research results in this paper lay a solid test basis for revealing the cave collapse and failure mechanism in super depth.
Highlights
As the main development field of oil reserve, the fractured-vuggy reservoir is the focus area of oil exploitation for the future [1]
The research results in this paper lay a solid test basis for revealing the cave collapse and failure mechanism in super depth
Since the discovery of the Tahe oil field in 1997, the oil output has risen from 3,900,000 tons to 83,600,000 tons in 2017 for these 20 years
Summary
As the main development field of oil reserve, the fractured-vuggy reservoir is the focus area of oil exploitation for the future [1]. In response to the collapse and failure phenomenon of the cave in super depth (with a buried depth of 5000 to 7000 m), the ultra-high pressure model test system with intelligent numerical control function is developed and the model simulation material meeting the similar conditions is prepared. This is the first time systematically revealing the collapse and failure process, the failure mode and the failure law of a carbonate cave in a super depth and comparing and analyzing the authenticity of the test result through the numerical method. The research result lays a solid test basis for revealing the collapse and failure mechanism of the cave in a super depth and has great theoretical significance and engineering application value
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
