{"title":"Caprock integrity determination at the Christina Lake Thermal Recovery Project, Alberta","authors":"G. Prost, J. Newsome","doi":"10.2113/GSCPGBULL.64.2.309","DOIUrl":null,"url":null,"abstract":"Abstract The Cenovus-ConocoPhillips Christina Lake oilsands project uses Steam-Assisted Gravity Drainage (SAGD) to recover bitumen from the Lower Cretaceous McMurray Formation at depths between 300 and 400 m. The McMurray Formation at the Christina Lake Field consists of fluvial to estuarine sands and muds capped by marine shales and sands of the Wabiskaw member of the Clearwater Formation. The SAGD process involves injecting steam under pressure to mobilize the bitumen, which is then pumped to the surface. The increased reservoir pressure is expected to be contained by the caprock. In the event of a failure of the caprock to contain these pressures the steam and oil may escape to shallower units and possibly the surface. This is not a desired outcome. We describe a process to characterize overburden and evaluate caprock strength. The minimum in situ principal stress is shown to be five times reservoir operating pressure and 2.5 times startup pressure. Compressive strength at the reservoir confining pressure of 4.5 MPa is six times operating pressure and three times startup pressure. The Wabiskaw member is shown to contain laterally continuous and impermeable semiconsolidated muds. Porosities and permeabilities are low and capillary entry pressure is high. A program of subsurface and surface monitoring is described.","PeriodicalId":56325,"journal":{"name":"Bullentin of Canadian Petroleum Geology","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2016-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2113/GSCPGBULL.64.2.309","citationCount":"15","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bullentin of Canadian Petroleum Geology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.2113/GSCPGBULL.64.2.309","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"Earth and Planetary Sciences","Score":null,"Total":0}
引用次数: 15
Abstract
Abstract The Cenovus-ConocoPhillips Christina Lake oilsands project uses Steam-Assisted Gravity Drainage (SAGD) to recover bitumen from the Lower Cretaceous McMurray Formation at depths between 300 and 400 m. The McMurray Formation at the Christina Lake Field consists of fluvial to estuarine sands and muds capped by marine shales and sands of the Wabiskaw member of the Clearwater Formation. The SAGD process involves injecting steam under pressure to mobilize the bitumen, which is then pumped to the surface. The increased reservoir pressure is expected to be contained by the caprock. In the event of a failure of the caprock to contain these pressures the steam and oil may escape to shallower units and possibly the surface. This is not a desired outcome. We describe a process to characterize overburden and evaluate caprock strength. The minimum in situ principal stress is shown to be five times reservoir operating pressure and 2.5 times startup pressure. Compressive strength at the reservoir confining pressure of 4.5 MPa is six times operating pressure and three times startup pressure. The Wabiskaw member is shown to contain laterally continuous and impermeable semiconsolidated muds. Porosities and permeabilities are low and capillary entry pressure is high. A program of subsurface and surface monitoring is described.
期刊介绍:
The Bulletin of Canadian Petroleum Geology is a peer-reviewed scientific journal published four times a year. Founded in 1953, the BCPG aims to be the journal of record for papers dealing with all aspects of petroleum geology, broadly conceived, with a particularly (though not exclusively) Canadian focus. International submissions are encouraged, especially where a connection can be made to Canadian examples.