Research and Application of Cement Plugging Techniques in Evaporite Bed of Piedmont Tectonic Belt of the Tarim Basin

摘要

Situated on the piedmont tectonic belt of Tarim Basin, well KS-37 encountered large-section evaporite bed at the depth from 5100m to 5400m. Complicated geological conditions and narrow pressure safe density window prevent the cementing plug project to some degree. 2.26g/cm~3 forerunner slurry, 2.26g/cm~3 saturated saltwater spacer fluid aggravated by micro-manganese and 2.30 g/cm~3 intumescence cement slurry, combined with corresponding technical measures have been utilized in the evaporite bed. As a result, cement plug operation has been accomplished successfully so as to meet the engineering requirements of side tracking. It is indicated based on field application that great progress has been made in the adoption of cement slurry of high density as well as corresponding technical measures, which can meet the requirements of plugging cement in evaporite bed in the condition of narrow pressure safe window.