Dynamic shaft pressure distribution prediction method and system under high-frequency switch well working system

• Main Authors: WANG RUIFEI, MA XIANLIN, TANG YING, ZHAN JIE, ZHENG ZIGANG, WANG JUNQI, LIN JIA'EN
• Format: Patent
• Language: Chinese; English
• Published: 22.04.2022
• Subjects: CALCULATING; COMPUTING; COUNTING; EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; ELECTRIC DIGITAL DATA PROCESSING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; PHYSICS

The invention discloses a shaft pressure distribution dynamic prediction method and system under a high-frequency switch well working system, a motion equation and a material balance equation are combined to obtain a water attack equation set, the water attack equation set is solved through a characteristic line method numerical value, and the change relation of pressure of each point in a shaft along with time is obtained. Dynamic prediction of shaft pressure distribution under the working system of the high-frequency switch well is realized by using the change relation of the pressure of each point in the shaft along with time; when the water attack equation set is solved, the opening degree of a wellhead valve serves as a wellhead boundary condition, the opening degree of the valve is controlled at a wellhead through a wellhead valve opening and closing rule, and the wellhead valve opening and closing rule adopts nth power of a cosine function; the well bottom boundary condition is that the liquid supply a