Method and device for determining original formation pressure of coal reservoir based on pressure after fracturing

• Main Authors: SHI JUNTAI, LI XINGHAO, LI WENBIN, ZHANG LONGLONG, WANG-TIAN DUOYI, YANG BO, JIA YANRAN, SHI GUIYUAN
• Format: Patent
• Language: Chinese; English
• Published: 21.09.2021
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS

The invention provides a method and device for determining the original formation pressure of a coal reservoir based on the pressure after fracturing. The method comprises the following steps of collecting the data of the coal reservoir; on the basis of the coal reservoir data, obtaining dimensionless oil pipe pressure and corresponding dimensionless time; carrying out linear fitting on scatter points with the dimensionless oil pipe pressure and the dimensionless time as coordinates, and obtaining a linear function; and obtaining the original formation pressure of the coal reservoir based on the intercept of a linear function. The method for determining the original formation pressure of the coal reservoir based on the pressure after the fracturing is wide in application range, and the problem that the original formation pressure of the coal reservoir in a low-pressure, low-permeability, low-yield and water injection pressure drop-free test well area cannot be determined is solved. 本申请提供一种基于压裂后压力确定煤储层原始地层压力的方