At the beginning of 2015, the Drilling Engineering Technology Research Institute of the Zhongyuan Project sent the good news that their independently developed sealed core worked successfully at the directional section of the Wen 268-1 Well, thus making a breakthrough in horizontal directional sealed coring.
The tool scored a core recovery rate of 100% and sealing percentage of 95.45% during the sealed coring experiment at the horizontal well with an inclination of 89.75 degrees. The coring position was the directional section of the Wen 268-1 Well in its east three group, with an inclination of 42 degrees. The section is prone to blocked core due to bad rock formation, easy breakage and dilatancy, thus affecting core recovery rate. With well-prepared core drilling parameters and meticulous operation, the engineers accomplished four barrels of coring, with 21.96 meters in penetration footage, 93.26% in core recovery rate and 94.48% in sealing rate, exceeding the designed targets.