Abstract
The Kelameili Gas Field in the Western China is a deep, naturally-fissured volcanic formation. The lithology, with significant degree of heterogeneity, varies from granite to tuff and breccia, has a low matrix porosity ranging from 4 to 10% and a permeability ranging from 0.015 to 0.026 md, and up to 984 ft in gross thickness.
Due to this low permeability proppant fracturing has been considered necessary on the conventional vertical well completions. However, the presence of natural fissures in the reservoir has often lead to the premature screenout of many treatments, resulting in lower than expected production.
The multi-stage proppant fracturing of DXHW-1 is a milestone for the operator due to: 1) The very first and the deepest horizontal well in a volcanic formation in China, been stimulated with a multi-stage proppant fracturing treatment; 2) The completion tubular and tools were designed for bottomhole pressure (BHP) up to 13,000 psi, and deepest coiled tubing (CT) cleanout (at 14,426 ft) was planned as contingency for any premature screenout.
This horizontal well was completed in five individual stages that were pumped continuously, one after the other, into the 2,454 ft openhole section using nine openhole isolation-packers. 341,270 lbs of 30/50 ceramic proppant was successfully placed into the formation, using a total of 7,981 bbls fracturing fluid. The well produced 35.3 MMscfd initially after the treatment and the production was stabilized at 17.65 MMscfd with wellhead pressure of 4,206 psi, which is four times higher than the average offset well.
The success of this treatment has supplemented additional 30% volume to the first gas station just from this single well, and also allows the operator to announce the discovery of an additional 3,637.4 billion ft3 of natural gas reserves in this field. Based on this success same completion model will now be used on future wells in the Kelameili Gas Field with several wells currently being planned.
