A multi-phase stimulation treatment was required and subsequently executed in deep-water Gulf of Mexico to remediate a multitude of damage mechanisms resulting from years of hydrocarbon production. Among the many challenges that deep-water operators must face, there is the need for remediation of wells experiencing a decline in production. The execution of these treatments can prove to be very costly and require extensive damage assessments to properly design the most effective stimulation plan. Treatment placement is a major part of the decision process and will impact the performance of the job. A well in the Mississippi Canyon field had an asphaltene deposition issue based on asphaltene onset pressure evaluations as well as suspected fines migration issues. Each requiring its own treatment protocol. This operation required that a rig be moved onto location so that the job could be pumped via coiled tubing to assure injectivity into the zone of interest.
A multiphase approach design included:
Phase I -a screen/near wellbore soak
Phase II- a diverted specialty solvent formation treatment to remediate asphaltene deposition.
Phase III- a diverted mud acid treatment that included specialty stimulation systems to address scaling, clay and fines issues.
The challenge is the difference between utilizing xylene alone for organic deposition removal verses specialty solvent treatments specific to asphaltene removal as well as the use of deep penetrating hydrofluoric acid blends and specialty additive packages.
Utilizing this multi-phase approach resulted in a successful treatment outcome for the operator. An increase in total fluids production, an increase in flowing tubing and a job pay off of less than 30 days was the result of finding a solution to these particular set of challenges.