Center for Energy Studies Louisiana State University Energy Coast & Environment Building Nicholson Extension Drive Baton Rouge, LA 70803, U.S.A. E-mail: mkaiser@lsu.edu
Over the past several decades, various methods have been proposed to evaluate drilling cost and complexity, but because of the large number of factors and events that impact drilling performance, predictive models are difficult to construct. Quantifying well costs and complexity is challenging, due either to restrictions on data collection and availability, constraints associated with modeling, or combinations of these factors. Drill rates are often constrained by factors that the driller does not control and in ways that cannot be documented. The Joint Association Survey and Mechanical Risk Index the most popular methods used to evaluate drilling cost and complexity in the Gulf of Mexico, and specialized indices have been introduced to characterize are the complexity of drilling directional and extended reach wells. Recently, the concept of Mechanical Specific Energy has been used to obtain a more objective assessment of drilling efficiency. The purpose of this paper is to review the primary methods used to assess drilling cost and complexity. The foundational basis of each approach will be described and a critical assessment of model assumptions provided.
Drilling performance, cost and complexity models, technical limit
