The challenge
A bullhead acid treatment with diverter pumped through the annulus was performed using the WellStim design. The post-stimulation production results showed 97.7% convergence with the modeled values.
- Area: Central Asia - Reservoir: Oil Carbonates - Depth: MD – 4,400 ft, TVDSS – 2,500 ft - Wellbore completion: Horizontal open-hole - Lateral length: 440 ft - Casing: 4.5” @ 4,000 ft - Tubing: 2.5” @ 3,900 ft
The solution
Production data history match was performed for the last 8.5 years. Key parameters including fluid rate, oil rate, water cut, pore pressure, bottomhole flowing pressure were matched with previous stimulations in the well. Skin change was estimated before and after every historical stimulation. The current skin was estimated as 2.1.
The acid job was done using WellStim design. Post-stimulation analysis of the actual treatment data showed high convergency of design vs actual parameters.
The results
Actual production data was uploaded to WellStim a few months after the treatment. WellStim production analytics module estimated the convergence of design vs actual parameters.
Design vs Actual oil production convergence is 97.7%.
The ability to calibrate a model to the geological and mechanical characteristics of the reservoir—using laboratory study results and accurate historical production data analysis, including current skin assessment—enables a high degree of convergence between predicted and actual parameters after acid treatment.