Abstract

Drilling horizontal wells is the common mode of operation for field development in low-permeability unconventional reservoirs such as the Eagle Ford Shale. Assumptions are made regarding the homogeneity of the reservoir as wells are drilled away from the vertical pilot well. It is assumed that the reservoir characteristics remain uniform and also that the structure is constant based on the dip of the beds in the pilot hole wellbore. Making such assumptions can lead to wells being placed out of zone and in rocks with much different reservoir quality and stress magnitude than those in the pilot hole, which can adversely affect the production potential of the well. With the high cost of drilling and completing these wells, it is generally economically beneficial to do some evaluation of the lateral to ensure proper placement of the well and also the optimal placement of completion zones along the lateral. Lateral measurements and petrophysical interpretations can be used to define variations in reservoir quality (RQ) and completion quality (CQ) along the wellbore, which can then be used to optimize the completion design, for example, placing perforation clusters in similar rocks to increase production when compared to peer wells completed with a geometric design. The next step in integration is correlating pilot and lateral wellbore measurements with the structural component. This process is defined as geology quality (GQ). After taking together, RQ, CQ, and GQ, a comprehensive design of a wellbore-specific completion treatment can be achieved. This methodology of integrating data from many sources provides a better understanding of the variability and structural challenges of these complex reservoirs.