It is well accepted by the Oil and Gas industry that approximately 30%-40% of perforations or perforation clusters do not contribute to the production of a multi-stage fracturing stimulated well. Diversion is a common method to maximize the wellbore coverage. The objective of this study is to evaluate and maximize the effect of diversion in multi-cluster horizontal well hydraulic fracturing applications using water hammer profile analysis, step down test and microseismic monitoring.

In this study, the authors demonstrated integrated approach for the well stimulation efficiency evaluation. A number of methods have been used for analysis: First, step-down tests after each stage have been used to estimate perforations accepting fluid. Second, innovative method of the high frequency surface pressure record analysis was used to detect diversion. Additionally, microseismic monitoring was used as an independent measurement that allows to validate the results.

Eight wells were hydraulically fractured with multiple clusters per stage. Each stage is separated either by frac baffles or plugs. Diverter was pumped to promote more uniform wellbore stimulation. Shut- in procedure was implemented after each diverter step. Signatures of water hammer during shut-in are recorded by high frequency pressure gauge and analyzed in real-time using advanced algorithm from speech processing domain. Locations of clusters receiving fluid were calculated and diversion results are qualified. Microseismic measurements in some of the evaluated wells and step down tests are also performed to qualify the diversion process. All of these measurements were done in real-time and utilized to maximize the number of frac propagations, which will have a positive impact on production. This engineering technique allows the operator to make informed real-time decision based on the effectiveness of inter-stage isolation and diversion. Small footprint high frequency pressure monitoring (HFPM) allows the optimization of cost/BOE ratio.