An Integrated Approach to Optimize Drilling, Completion and Hydraulic Fracturing Performance in Unconventional Wells

Abstract

In the age of artificial intelligence, digitalization, rising energy demand, falling prices of barrel of oil and increasing difficulty in oil & gas recovery we need to have an integrated approach based on physics, artificial intelligence and rock mechanics to reduce the non-productive time in drilling and -in parallel- enhance well production. The integrated approach should help in reducing cost, minimize human intervention, reduce drilling associated risks, minimize the negative impact on near wellbore rock behavior due to stimulation and enhance the recovery of hydrocarbons.

Stuck pipe is a major stake holder in "non-productive time" and is estimated to cost the oil and gas industry around $250 to $300 Million a year. Stuck pipe due to wellbore stability issues is a regular phenomenon while drilling weak zones in minimum stress direction especially in Middle East. William Lyon's in 2010, estimated that cost of stuck pipe in deep oil and gas wells is around 25% of overall budget.

To counter stuck pipe, for instance, drilling engineer may decide to increase the mud weight inorder to minimize the wellbore stability issues, and this could enhance challenges to a stimulation engineer associated with potential damage. Simliarly, an improper acidizing could soften the rock and negatively impact mechanical response of near wellbore rock during production. Two simple examples demonstrate the value of an engineering holistic approach based on wellbore stability integration into hydraulic fracturing treatment design considering the complexity involved around geomechanics.

This study introduces a workflow that holistically integrates a rock mechanics approach to optimize drilling performance and characterize the stresses around the wellbore with the completion design, combining the geomechanical and petrophysical properties to optimize the completion and stimulation design. This engineering workflow will enable to design and customize a particulate diverter system for effective fluid diversion and wellbore coverage by uniformly distributing the stimulation fluid with an aim to create fracture network complexities, enhancing the production. Additionally, this paper showcases the learnings from various field case histories including but not limited to drilling across weak bedding plane from Asia, wellbore stability issues in Middle East that resulted in high non-productive time from drilling, Uniform Fracture Growth from Horizontal Wells and re-fracturing strategies from North and South America.

This approach will enable optimizing well performance from drilling to production, minimize risks and optimize intervention by retro alimenting each phase of the process to the next. This workflow provides a innovative strategic approach optimizing drilling, completion and stimulation mitigating challenges in unconventional formations that can be extrapolated to conventional reservoirs as well.