Perforating Technologies For Under Balanced Well

There are 4 big difficult problems in perforations under balanced well: perforation under wellhead pressure,snubbing operation throughout perforating process,low confining pressure perforating operation and the fullbore string convenient for the following operations.This article explained three types of perforating methods,namely the fullbore perforating technology,anchoring perforating technology and wireline conveyed perforating(WCP) technology under wellhead pressure.The first technology may automatically throw away the primer detonator core,perforator debris under balanced perforation after completing the tubing conveyed perforation(TCP) operation so that whole perforating string becomes a fullbore production string.The second technology uses specific modular perforator and suitable wellhead wireline lubricator to pick up the perforators.The modular perforator means that the perforator in the oil well is separated into independent modular units so that we can pick it up in segmentation under pressure within the height of lubricator to realize snubbing operation throughout perforating process.The third technology uses wellhead high pressure lubricator,big diameter perorator and high quality perforating fluid to implement perforation under balanced pressure when the well pressure is equal to or below the formation pressure,therefore,preventing the pay zones.The above three uechnologies are better used in perforating jobs.