Targeted Perforating in the Granite Wash Based on Traced Cement Spacer Leakoff

Abstract

Completion diagnostics have been applied in Granite Wash wells in the Texas panhandle and western Oklahoma for decades. When applied in horizontal wells, these diagnostic data have shown that the perforation clusters are not always evenly stimulated. In an effort to place the perforation clusters across desirable reservoir targets, engineered perforating has been utilized. In order to target desirable natural fracture swarms and higher porosity streaks, an effort was made to identify those features by taking advantage of the propensity for completion fluid leakoff to occur into those features immediately prior to pumping cement. If enough differentiation is evident using some form of completion diagnostics, then those features that capture the traced completion fluid can serve as targets for the subsequent engineered perforating. In this paper, gamma-emitting particulate tracers were mixed in the spacer fluid used to separate the drilling mud from the cement with the expectation that this traced spacer fluid would leak off into some of these targeted features, and those tracer captured features could then be identified with a spectral gamma ray logging tool after pumping cement. Subsequently, the proppant used to hydraulically fracture those same intervals could be traced with other gamma-emitting particulate tracers to determine if those targeted features had been successfully fractured. This paper will compare and contrast the spectral gamma ray logs run after circulating the traced spacer fluid and cement and after pumping the traced hydraulic fracturing treatments. The diagnostic data will also be compared with well performance data for these wells.