Applications of Small Diameter Cross Dipole Sonic and Micro-Resistivity Imaging Logging Tools in Conventional and Unconventional Reservoirs

Williams, Peter
Weatherford, Loughborough, United Kingdom.

Sonic logs and micro-resistivity imager logs have broad application in geological, petrophysical and geomechanical studies. New small diameter wireline-style logging tools with memory capability reduce the acquisition risk and extend the application of these data into wells that are technically or commercially challenging for conventionally-sized tools. These include slim wells, high dogleg severity wells, horizontal wells and wells where logging out of drill pipe may be the only cost-effective evaluation option.

The innovative design of the small-diameter memory cross dipole sonic tool allows compressional and shear velocities and shear anisotropy to be determined from a small package that is not constrained by wireline data transmission rates.

The small-diameter memory micro-resistivity imaging tool has demonstrated that borehole coverage and image quality match or exceed those of previous generation tools.

The tools may be deployed on wireline, through drill pipe, or without wireline inside a drill pipe shuttle; the latter facilitates access into highly deviated wells and past bad hole conditions without compromising borehole coverage.

Logs from both conventional and unconventional reservoirs demonstrate the robustness of the data over a broad range of common environments. Results have been applied to the description of clastic and carbonate reservoirs,surface and borehole seismic correlation, in-situ stress orientation, natural fracture identification, hydraulic fracture design, permeability estimates and new well placement. Performance is reviewed from operations around the world and case histories are presented.

AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012