Research on Gel Plugging Technology of Coalbed Methanein Deposit

Daji block is an important arear of producing and energy in Lifen block of coalbed gas. There are the natural leak-causing crack, water in the formation, narrow security density window, serious leakage and poor plugging in this area. In order to solve the problems, this paper adopted the compound gel plugging technology, which has the advantages of both supramolecular organic gel and inorganic gel, to prevent leakage in this well area. Laboratory tests show that the safe construction time of the composite gel can be controlled within 1-1.5 hours, and the pressure bearing capacity of cracks of 4.0 × 3.5 mm and 3.0 × 2.5 mm can respectively reach 3.3 and 4.5 MPa. It has strong cementing ability to rock particles, and the pressure bearing capacity of 14cm squeezed into the 6-8 mesh sand filling pipe can be 5.6 MPa. Field application show that the special gel technology have the characteristics of easy pump injection and simple construction as well as improve the plugging effect of Daji block.