SALT BED Ф195MM CORING PRACTICE IN WELL JINZI-1

Well Jinzi-1 is drilled to provide the formation petrophysical data for the secure design of underground gas storage project used for west to east gas transportation, thus large size cores need to be obtained for reliable data and information, and therefore LY-195 coring tool, which is the largest diameter available domestically was used for coring in this well. As large size coring tool may cause such problems as severe blockage and difficult core cutting off, a serious of engineering measures were taken, e.g., timely change of bit, stop drilling and then fast rotation to cut off the core, control the bit cutting ID, improve ROP, etc. Coring was conducted from 986.44~1016.44 m, and a core as long as 29.57 m was obtained with core recovery rate of 98.6%.