Exploratory Test of Horizontal Drilling Plugs and Water Shutoff Technology in X Horizontal Gas Well

Abstract

In order to solve the problem that the tight gas X horizontal gas well could not be put into production due to the accumulation of fluid in the wellbore during the drainage stage after fracturation, based on the geological understanding of water flowing from the far end of the reservoir, and the actual situation of staged fractured with drillable bridge plug, water blocking has become the exploration direction of potential excavation and resuming production. Through the analysis of the type, structure, setting principle and unsealing principle of drillable bridge plug, put forward the technical idea of horizontal drilling plugs and mechanical water plugging. And determine the treatment method of drilling-grinding and fishing large inner diameter bridge plugs, and design the construction process. Moreover combined with theoretical calculation, the relationship between the debris carrying velocity and displacement in horizontal wells, the size of the debris and the angle of inclination was optimized. Besides that, the milling method that uses a wellhead rotating device to drive the drill pipe and grinding shoes for drilling and grinding was proposed. In the field test, successfully drill to the third large inner diameter bridge plug position according to the design requirements. And successfully put in the fishable bridge plug to achieve mechanical water blocking. After commissioning, the daily gas production volume reached 11000 m3/d. The test results show that: 1) It is feasible to use the wellhead rotating drive drill pipe and grinding shoes to drill and remove the steel drillable bridge plugs in the horizontal section of the horizontal well; 2) It is also feasible to use the fishable bridge to plug in the horizontal section of the horizontal gas well with drillable bridge plug staged fractured, and the plugging effect is good. In summary, it is shown that this technology test achieves the purpose of potential excavation and resuming production of the X horizontal gas well, which has good reference value.