Method and device for extracting depth of mud invading stratum in petroleum drilling

• Main Authors: WANG LEI, LIU ZHONGHUA, ZHOU CANCAN, FAN YIREN, CHENG XIANGZHI, ZHAO SHUANG, YUAN CHAO, LI CHAOLIU, LU YINGLONG, WU YIZHI, SONG LIANTENG, LI XIA
• Format: Patent
• Language: Chinese; English
• Published: 27.04.2021
• Subjects: DETECTING MASSES OR OBJECTS; EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; MEASURING; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; PHYSICS; TESTING

The invention provides a method and device for extracting the depth of mud invading a stratum in petroleum drilling. The method comprises the steps: acquiring array lateral resistivity logging information; obtaining a resistivity ratio cross plot from a pre-established plot library according to the invaded zone resistivity reflected by the array lateral resistivity logging data, wherein the plot library comprises a plurality of invaded zone resistivity and resistivity ratio cross plots established by resistivity curves of different detection depths under each invaded zone resistivity condition; according to the array lateral resistivity logging data and the obtained resistivity ratio cross plot, determining the depth of the pre-estimated mud invading the stratum; and according to the estimated mud invasion stratum depth and the array lateral resistivity logging information, selecting a resistivity ratio cross plot adaptive to the estimated mud invasion stratum depth from the plot library, and extracting the a