Case Study: 1300 Wells Saved From Expensive Workovers Or Shut-ins
A large independent crude oil and natural gas producer with significant interests in the Clearwater Formation in Northern Alberta was operating wells initially established in the late 1990s using CHOPS (Cold Heavy Oil Production with Sand). The horizontal sections of the wells extended beyond 2,400 meters and each well was completed with 0.250” straight slotted liners. As the profile of the well formation changed over time, there was an increase in the level of water production and the operator turned to polymer flooding as its primary Enhanced Oil Recovery (EOR) strategy.
Ultimately, the effects of the polymer injection process and pore pressure depletions resulted in fines migration and increasingly high volumes of sand production. Workovers determined the wells were plugging off with sand and the operator was concerned that production was restricted to the heel section of the well. The Operator challenged RGL to develop a solution that would optimize the production levels of each well by designing, engineering and manufacturing a sand control solution that would:
- Mitigate sand production while allowing the fluid to flow free and unabated
- Handle the installation loadings to total depth (TD)
- Ensure an economically appropriate “fix” for the current low oil-priced environment in which it was operating.
While all sand control technologies were initially considered, the cost, strength and performance of slotted liners in long horizontal wells was deemed the most economical and technically appropriate recommendation. RGL proposed recompleting the wells with 0.020” straight slotted liners set within the existing 0.250” liners. The Company conducted Particle Size Distribution (PSD) analysis from core sand and bailed sand samples, as well as finite element analysis (FEA) and torques and drag analysis to ensure the new liners could withstand the installation loads and reach TD without compromising the long-term sand control performance
After numerous well cleanout trials, the 0.020” was successfully completed to the wells’ total depth (TD). Completion techniques were revised with forward vs. reverse circulation methods, heavy weighted fluid, and lubricants to ensure the wells were free of sand and remained so while running in hole.
Utilizing RGL’s engineered solution, the operator was able to take advantage of a robust, cost efficient sand control solution and recorded marked improvements in well performance related to:
- The elimination of expensive sand cleanouts and/or shut-ins
- Increased oil production (<50 bbl/d to >150 bbl/d)
- Decreased water production (30% WC to 10% WC)
- Low cost completion
- A scalable, 1300-well solution