Method for evaluating contribution of spontaneous imbibition to gas-water alternating oil displacement efficiency

• Main Authors: GUO YABING, XIAO PIAOFU, WANG RUI, HU WEI, TANG YONGQIANG, YANG YANG, LANG DONGJIANG, CUI MAOLEI, ZHAO CHUNPENG, LUN ZENGMIN
• Format: Patent
• Language: Chinese; English
• Published: 24.10.2023
• 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 discloses a method for evaluating the contribution of spontaneous imbibition to gas-water alternating oil displacement efficiency, which comprises the following steps: carrying out a stratum oil-water distribution environment simulation experiment on a to-be-evaluated target layer rock core to obtain a first nuclear magnetic resonance characteristic of the rock core in an original oil-water distribution state; carrying out a single gas-water displacement experiment to obtain a second nuclear magnetic resonance characteristic of the rock core in a gas-water displacement remaining oil distribution state; sequentially carrying out a spontaneous imbibition simulation experiment and a single gas-water displacement experiment so as to obtain a third nuclear magnetic resonance characteristic of the rock core in a spontaneous imbibition displacement remaining oil distribution state; and quantitatively evaluating the contribution degree of the spontaneous imbibition effect to the CO2 gas-water oil displa