Technical and Economic Evaluation for Wire-line Coring in Large Diameter Deep Drilling Project in Salt Basin

According to the characteristics of wire-line coring drilling technology and combined the project of ZK3 borehole in salt exploration in Ye-wu sag in Henan province, the data of construction cost and efficiency for wire-line coring and roundtrip coring separately have been analyzed. In a certain evaluation period, the technical and economic evaluation for wire-line coring and simulation roundtrip coring in ZK3 borehole conducted by net present value (NPV) method, the result shows that, in ZK3 borehole, comparing with roundtrip coring, the drilling efficiency of wire-line coring method improved by 85%, the profit is 6.3 times than roundtrip coring, its technical economy is more obvious along with the depth increase. The sensibility analysis shows, the most sensitivity factors effecting on the borehole efficiency are construction price and construction period.