Patent ID: 7387161

Claim:
A method for optimizing the shut-in time during the hydraulic fracturing of a subterranean reservoir rock formation and the injection of a quanity of a specified type of curable resin-coated proppant (CRCP) particles to maintain the fractures, where the shut-in time is the period during which pressure is maintained to effect curing of the resin coating to form a proppant pack of maximum strength, the method comprising: a. determining the temperature and pressure values of the reservoir during the fracturing process based on historical data; b. preparing a mathematic representation of the temperature recovery of the fractured formation in the form of a temperature recovery shut-in data source; c. preparing a test sample of CRCP sample of the type to be used in the fracturing process; d. placing a quantity of the CRCP sample in pressurized vessel at ambident conditions; e. placing velocity transducers in contact with opposing sides of the CRCP sample contained in the pressure vessel; f. sealing the pressure vessel and applying an external hydrostatic force of predetermined value to the CRCP sample; g. increasing the temperature of the CRCP sample in the vessel at a predetermined rate to thereby effect the gradual curing of the resin; h. activating the velocity transducers at predetermined time intervals to transmit waves of a predetermined fixed frequency as the temperature of the CRCP sample increases; i. measuring the acoustic velocity of the waves passing through the CRCP sample when the transducers are activated; j. recording the temperature of the CRCP sample at which the maximum wave velocity is attained, said temperature corresponding to the temperature at which the resin coating on the proppant is cured; k. correlating and recording the value of the temperature as determined in step (j) with the time required to reach said temperature from a temperature recovery shut-in data source; l. injecting an effective quantity of the type of CRCP prepared in step (c) into the fractured formation; m. maintaining the pressure for a shut-in time that corresponds to that determined in step (k) to establish a cured CRCP pack of optimum strength; n. returning the formation to production.