Formation identification method for coring during shallow optimal and fast drilling based on configuration interface control

The sand bodies in the Mingxia member in shallow Neogene reservoirs, Bohai Oilfield show thin, scattered, and miscellaneous characteristics, in addition, due to various factors such as engineering, geological conditions, and manual influences, traditional formation identification methods struggle to accurately compare and determine the coring layer during optimal and fast drilling, which results in excessive penetration and low sandstone recovery rates. To address this issue, a method combining configuration interface constraints and drilling parameter variations was proposed to determine the cyclic points of formation identification. Firstly, based on logging and drilling data, a configuration interface division scheme was formulated, and configuration analysis was performed on the drilled wells, establishing a closed and isochronous configuration framework for the target area. Then, real-time drilling data was input into the configuration framework to analyze and pick up layer interfaces, predicting the position of coring sand bodies. Finally, based on drilling parameter variations, drilling was stopped in a cyclic manner to determine whether coring is required. This method was applied to three wells in the Bohai Oilfield, and on-site testing show that it can achieve precise layer identification within 2.0 meters in the context of optimal and fast drilling. This significantly improves the coring efficiency and quality during drilling, contributing to cost reduction and efficiency improvement.