Determination method for free gas saturation and gas content ratio of deep coal bed gas

• Main Authors: SHI JUNTAI, CHEN MING, DENG TING, CAO JINGTIAN, WANG CHUNQI, HUANG HONGXING, XIONG XIANYUE, JIA YANRAN
• Format: Patent
• Language: Chinese; English
• Published: 30.01.2024
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; PHYSICS; TESTING

The invention relates to the field of gas reservoir development, and discloses a method for determining the free gas saturation and the gas content ratio of deep coal bed gas, which comprises the following steps: acquiring basic parameters of a deep coal reservoir, the theoretical ton coal adsorption capacity, ton coal non-adsorption gas content, square coal non-adsorption gas content, coalbed methane dissolution coefficient, gas volume coefficient and square coal maximum dissolved gas content are determined according to the basic parameters, then the free gas saturation is determined, and then the percentage proportions of adsorption gas, dissolved gas and free gas are determined by using the free gas saturation. The determination method provided by the invention can effectively determine and evaluate the free gas saturation of the deep coal bed gas and the gas content ratio of different occurrence states, the required parameters are few and are easy to obtain, and the operation is easy; in addition, the det