Publications

The structural information from seismic is normally used for releasing and drilling of wells. In the absence of good seismic information (complex geology, noisy seismic data etc) it is imperative that this information is supplemented with external geologic knowledge. To supplement the seismic information operators frequently rely on dips from bore hole images for delineating geologic structures.The borehole images investigate geologic structures in the vicinity of the well bore and are affected because of the borehole irregularities. Also the borehole coverage is smaller in large hole size causing an uncertainty in the dip estimation using geometrical method. In spite of some of these shortcomings image based dip measurement is still the favored methods for estimation of the dip and azimuths of reservoir.There have been numerous studies in the laboratory confirming the dip estimation from induction based measurements. With technology advancements, now it is possible to estimate the dips and azimuth from a new tri-axial wireline induction measurements in a bore hole environment. One of the main advantages that they look deeper than the image based dips and are not affected by the near well bore deformation.This measurement has been possible because of the co-located transmitter and the receivers in the tool rendering reliable measurements of dips and azimuths of the bed. The tri-axial measurements also provide the vertical and the horizontal resistivity of the formation which facilitate identification of hydrocarbon bearing reservoirs in low resistivity layers.Comparison of the dip and azimuths from the wireline induction tool with the image based dips has been discussed in this work. The dip information also provides increased understanding of the structure and is able to complement decision on future well location. The anisotropy measurements from the same tri-axial induction measurements also provide realistic saturation measurements. The saturation measurements are important input to the dynamic reservoir simulation for history match purposes.