Print this pageGeoscience Technology in the Planning, Drilling, and Post-Drilling Evaluation of Horizontal Wells
MATHISEN, MARK E.
Increasing horizontal well (HW) activity and continuing technical advances are leading to improvements in HW geoscience technology which increase hydrocarbon recovery and reduce costs. This paper provides a review of the geoscience technology necessary for the successful planning, drilling and post-drilling evaluation of horizontal wells. Since different types of geoscience data and interpretation may be required during the various phases of a HW program, the review is divided into planning, drilling and post-drilling reservoir evaluation sections. In the planning section, the geoscience technology necessary to define well objectives, location, target zone(s) and well path is reviewed. Examples of the geoscience input, or variables to be evaluated by reservoir modeling and simulation are also discussed. Once the well path is chosen, aspects of drilling methods/materials needed to reach the target, the need for a pilot hole and coring are discussed, followed by a review of logging program tools, methods and limitations. Drilling phase geoscience data include MWD/LWD/geosteering and mud log data, as well as the optional acquisition of borehole seismic data. Drilling phase data acquisition and geoscience interpretation require input from an interdisciplinary team to guide the bit to, and through, the desired reservoir zone. Post-drilling HW reservoir evaluation includes the interpretation of commonly available MWD/LWD logs, the optional acquisition and interpretation of MAD wireline logs, horizontal core description and analysis, core-log calibration, reservoir seismic interpretation, and the development of an integrated geoscience reservoir model. Ongoing and future developments in HW geoscience technology are also discussed.