The development of field E was designed for maximum optimization resulting in the drilling and completion of two wells. Well A was drilled and completed with an open hole gravel pack (OHGP) completion targeting the oil reserves, while Well B utilized a cased hole gravel pack (CHGP) completion to access the gas reserves. This paper focuses on the challenges of completing Well A and the solutions implemented for the successful completion and delivery of the well. The main challenge faced in well A was in balancing the borehole stability requirement and the low fracture gradient. Increasing fluid density to maintain borehole stability has an inverse correlation to the marginal pressure window. A novel approach was applied on both the Wellbore Cleanup (WBCU) and the OHGP operations with modification on the completions hardware, procedure, and execution to finely balance the Equivalent Circulating Density (ECD) to maintain borehole stability while staying below fracture pressure. During the OHGP operation, dynamic ECD tracking was put in place and additional back pressure was applied to maintain that balance. Meticulous checks were conducted during the planning stage with independent design and calculations performed to ensure there were no red flags in the implementation of the unconventional operations planned. Gravel pack tool with anti-swab capability was selected, ensuring hydrostatic communication with the formation was maintained in all the stages of the job prior to the OHGP. For the OHGP, shunted sand screens and diverter valves were incorporated with a low friction viscoelastic fluid system and lower density completion brine. Utilizing these hardware and fluid systems allowed the use of different completion brine weights that sustained the borehole stability while alleviating the overall system friction which maintained the ECD below fracture pressure during the OHGP. As the OHGP progressed, the system ECD was predicted to fall below the threshold required for borehole stability. To maintain the borehole stability, back pressure was applied on the annulus to gain additional ECD. The OHGP was completed successfully with no losses observed throughout the job. Post job analysis on the data collected from downhole memory gauges showed the bottomhole pressures to be tracking the ECD and the fracture pressure as planned. It also confirmed the packing sequence was as designed with 100% pack efficiency achieved.
Moses et al. (Mon,) studied this question.