Geological Factors Affect Horizontal Well Completions

Abstract

Objectives/Scope: Horizontal wells provide completion problems that are not typical in vertical wells. Horizontal wells traverse multiple layers of depositional surfaces within reservoirs and can cross multiple deposition types in a single lateral. Each of these geological boundaries may be problematic when attempting to effectively fracture treat these wells. Defining these features would be useful in the completion design. Methods, Procedures, Process: Dipole sonic logs were added to the evaluation program in an attempt to understand these parameters. These logs were run in an open-hole environment and then again after casing was set. Evaluation of the location within the formation is a valuable result of acquiring these logs. The effect of this relative location and the effect of the efficiency of the fracture treatment is now possible. Results, Observations, Conclusions: The well path was identified within the reservoir package and when boundary conditions were crossed extending into the adjacent horizon. Fracture-treatment placement was seemingly affected by the proximity of the well path to these boundary conditions. Anisotropy from the cased-hole log tends to more consistently reflect breakdown-pressure conditions observed in the treatments. Identifying these geologic features can change the expected placement efficiency of any treatment program. Novel/Additive Information: The ability to understand the relative placement of the wellbore within any geologic condition results in increased accuracy in the anticipated treatment behavior. The breakdown pressure can be minimized by the inclusion of this geologic context.

AAPG Datapages/Search and Discovery Article #90217 © 2015 International Conference & Exhibition, Melbourne, Australia, September 13-16, 2015