Rigless Abrasive Perforating and Fracturing in Horizontal Tight Gas Wells

Abstract

This particular field is a mature gas field. It produces gas and condensates. The reservoir consists of low permeability sandstones deposited in a fluvio-tidal to littoral environment. The last one can be classified as "Tight Gas" reservoir, which requires fracture stimulation treatments. The reservoir characteristics led to think about non-conventional designs of the wells and their completions. The approach of completing a ca 1700 m TVD / 3000 m MD cemented horizontal well was the challenge. As a result of this process, new technologies were applied for the first time in the region. Among others, abrasive perforating using state of the art coiled tubing tools; multiple zones stimulation, creating orthogonal fractures in the horizontal section; the use of composite frac plugs and special sand bridge plugs for zonal isolation. On the other hand, the analysis and the inherent operational learning curve led to important logistic and economic benefits, ie a rig-less completion operation. One of the final steps of this process, the completion of the first well, was carried out on December 2009. Six frac stages were successfully performed using sand jetting perforating technology, composite bridge plugs, enhanced proppant bridge plugs and ultra light weight proppant, among others. This paper summarizes the process of selecting the best options for completion sizes for an optimized production, CT tools and strings, the design, operational planning and results of the application of the above described completion techniques.