Pre-Intervention for Multistage Frac Operation: Abrasive Perforation Challenges and Lessons Learnt

Abstract

The Plug and Perf technique is the most common application used in completions or horizontal wells that require multistage hydraulic fracturing. Once the horizontal well is drilled, cased, cemented and isolated - two runs of coiled tubing will be required. The first coil tubing run will be to clean up residual cement and the second run to convey the first set of perforating guns to the end of the well or toe. Once the perforating guns are initiated and perforated holes through the casing and cement into the formation, fluids can now be pumped into the formation. This injected fluid is required to push the WireLine bottom hole assembly (BHA), containing a frac plug to the target depth. The use of pressure-activated toe valves or Toe Injection Valve (TIV) in a completion string is yet another innovative approach to completing a horizontal well. This technology eliminates the need for perforating guns prior to a multi-stage hydraulic fracturing (frac) operation. Subsequently, the operator can greatly reduce costs when the need for coiled tubing (CT), wireline (WL), or workover rig (WOR) is no longer needed on location to convey perforating guns. However, if the completion is not equipped with Toe Injection Valve TIV or when injection rate through it is not adequate for wireline pump-down operations, or the toe valve (TIV) fails to open, in this cases the operator must rely on the conventional methods of perforating in order to achieve injection into the well and begin the frac operation. The conventional method will negate any cost savings that the TIV was designed to provide. In this paper will review cost effective solution using a motor BHA and abrasive perforator in tandem to clean-out, perforate make another clean out, test the infectivity and Pump acid if needed all in one run using by-pass abrasive tool.