Research and Application of Temporary Plugging Technique for Millimeter Hole Leakage

In order to solve the problem of oil well production being unable to recover due to fluid leakage during the workover operation of low-pressure and large pore reservoirs in Dagang Oilfield, an elastic and changeable temporary plugging agent was developed to improve the pressure bearing capacity of the system. At the same time, based on the “strong chain” and “ideal filling theory”, it was mixed with biodegradable plant temporary plugging materials to increase the temporary plugging capacity of the system. In addition, a certain amount of auxiliary agents such as anti-swelling agent, thickener, drainage aid, etc. to form a temporary plugging and leakage prevention technology suitable for millimeter hole leakage. The technology is effective at the aperture is below 3 mm, the pressure is below 5 MPa. The API is 15 ml/30 min, the recovery of permeability exceeds 90%. So far, the technology was successfully applied in 8 wells, success rate is 100%, the average recovery rate of the well yield is 100%. The problem of leakage in high permeability reservoirs has been effectively resolved.