Slimming the Wellbore Design Enhances Drilling Economics in Field Development
Staying ahead of the curve sometimes requires reconsidering standard practices and vintage processes. One example that clearly illustrates this approach in the energy industry consists of planning solid expandable tubular technology into the casing design as a means to slim the wellbore. By incorporating the solid expandable tubular system at the beginning, the operator achieves a slimmer well profile while still maximizing hole size at total depth (TD), reduces drilling time to TD and reduces drilling costs. An operator in Texas epitomizes the advantage of this approach by using the 6 x 7-5/8 in. expandable openhole liner in deep gas wells to proactively address zones prone to loss circulation. The operator maintained hole size and realized significant worth from this enabling technology. This proactive approach saved the operator over $1M per well. Applying this technology across field development projects leads to substantial savings. For these wells, using solid expandable tubular systems to achieve a larger wellbore at TD resulted in the following features, advantages and benefits: • Higher rate-of-penetration (ROP) in long intermediate casing section (36% enhancement) • Overall drilling cost savings (15-20%) using slimmed wellbore vs. big bore pipe program • Improved drilling performance and lower equivalent circulation density (ECD) below the solid expandable tubular system This paper will detail how the planning and application of solid expandable tubular systems resulted in significant benefits. Drilling conditions, circumstances and environments will be discussed to illustrate how solid expandable tubular technology is conducive to efficient drilling operations. In addition, this paper will discuss the value realized from expandable applications and how these systems enhance the value of the customers’ assets.