Application of Coring Technology in the Loose Sandstone

Abstract:

Sandstone coring is a drilling technical problem that has not been completely solved so far. There are many kinds of sandstone, but they all have the same characteristics: loose structure, no cementation or slight cementation, expansion in water and good permeability. Core recovery is low in sandstone drilling and the borehole is easy to collapse. In order to solve the technical problems in sandstone coring drilling, a set of sandstone coring technologies has been summarized by the study on drilling process technical parameters, coring device structure, drill bit optimization design, mud formula, drilling machine matching, core getting by core sintering with drill and core collecting by water pressure, and has been applied in the actual drilling production. All the technical indexes met the geological requirements, which provide valuable experience for core drilling in in-situ leaching sandstone.