RU96111794A - METHOD FOR REMOVING OIL FROM CRACKED POROUS LAYER-COLLECTOR - Google Patents

Claims (3)

1. A method of extracting oil from a fractured porous reservoir, comprising setting periodic operation modes of producing wells with a high content of displacing fluid in the product, characterized in that the oil is extracted through each individual well in several stages, before each of which a stationary mode of operation is set the corresponding well, on which the oil content of the well’s production is estimated, then the pressure recovery curve and the overflow are recorded for this well ny well on periodic operation by alternating starts and stops at the latter equal to each other at fixed intervals modes injection wells so that the frequency of the periodic mode is a step function of time with the first level stage of the first stage is determined by the expression

where τ ₂ , 1, i are the values of the time constant of the system of porous collector blocks, determined experimentally separately for each well from the pressure recovery curves before the start of each stage;
n is the number of the step;
i is the stage number;
1 - well number;
k is a positive number such that 1 <k <4,
and levels of subsequent stages of the first stage, decreasing each time with an increase in the number of steps by one by an amount that provides a change in the oil content of the products of the corresponding well with respect to the stationary mode of operation sufficient to control the effectiveness of the action, while the step lengths of the step function are made equal to the lengths of time during which the oil content of the product is increased relative to the stationary mode of operation, plus the time required for the placement of oil from the corresponding region of the formation to the mouth of the drainage well, the duration of the stages of oil recovery make it so that the next increase in the stage number per unit no longer leads to an increase in the oil content relative to the stationary mode of operation of the well, the number of stages of oil recovery through each individual well is limited by the stage number i = N such that the oil content of the products of the corresponding well at i = N + 1 and n = 1 becomes equal to that observed in the stationary mode during the operation of the well, and the steps, starting with i = 2, completely repeat the step with i = 1.  2. The method according to claim 1, characterized in that the steps with odd number i completely repeat the step with i = 1, and the steps with even number i repeat the step with number i = 1, but with the reverse order of changing the frequency of exposure. 3. The method according to claim 2, characterized in that the duration of the stages of oil recovery is such that the number n _{max of} steps in the law of changing the frequency of exposure within each stage is set in accordance with the expression