Well completion method

Abstract

An improved method of completing unconsolidated subterranean formations is provided whereby the necessity of expensive high density brine completion fluids is eliminated. Also, the drilling rig time is eliminated or reduced. In one embodiment, the method involves placing a bridge plug below the zone, and displacing drilling mud with a lighter weight completion fluid such as potassium chloride fluid whereby the lighter weight completion fluid does not in itself create a sufficient bottom hole hydrostatic well pressure to control the well. Except for monobore/tubingless completions, a production packer and production tubing string may be placed in the well, if not already in place from a prior completion. The wellhead tree is placed on the well, two subsurface safety valves may be installed in the tubing, and the rig may be released from the wellsite. Sufficient pressure may be applied at the surface to thereby increase the bottom hole hydrostatic pressure to amount sufficient to control the well. The zone is perforated through tubing with an electric line conveyed gun under pressure. A dual-screen (vent-screen) device to control formation sand production is deployed on electric line, braided line, or coiled tubing. The dual-screen device is placed on top of the bridge plug, and the well is Frac Packed, or gravel packed down the tubing. The excess proppant/sand is then flowed from the well, or coiled tubing is used to wash the excess out of the well. The zone is then put on production.