Publications

Coil Tubing operated in NL wells, South Sumatera because of depleted reservoir pressure. Objective of coiled tubing operation are sand clean-out and acid stimulation to restore well productivity. Previously in NL wells has used a snubbing unit in intervention well but the results were not good. Formation damage was suspected due to packer fluid introduced into formation during snubbing job. Production optimization in brownfield is required to extend the economic producing life of the field using cost-effective and low-risk technologies. Well stimulation is generally proposed to enhance well productivity by acidizing treatment. Acidizing in sandstone applied in Medco to improve well productivity. But loss problem got in conventional rig operation during killing well in low reservoir gas well. Coiled tubing (CTU) can solve the problem and can operate without killing the well. Recipe acid HCl 15% get optimum in solubility test around 28-31%. Coiled Tubing Operation applied pulsonic method to get optimum result. After CTU Job (clean sand out & acidizing), well productivity improved refer to gas rate and flowing well-head pressure (FWHP) monitoring. Initial gas gain was more than 2.5 MMSCFD from 2 wells (NL-X1 and NL-X2) that were treated with CTU acid stimulation. Gas cumulative is around 176 MMSCF (3 months production) and still counting. Further evaluation will be conducted by performing complete well test (transient analysis). As conclusion, coiled tubing operation has proven to become effective well intervention in depleted gas wells to improve production optimization and open the opportunity to unlock potential in other wells which experiencing similar challenges. This paper shares case study, how to develop acid stimulation strategy covering guideline in acid selection and deploy acid without killing well in South Sumatra.