Heterogeneous tight sand challenges gas production

The Ordos Basin is the largest onshore gas-producing basin in China. Lateral heterogeneity and a high Young's modulus create technical challenges for successful gas production from the tight sands. PetroChina Coalbed Methane Company Ltd. (PCCBM) wanted to maximize efficiency for the multistage stimulation of a 4.5-in cased horizontal well in the Daji Field.

Salik local-sand-enabled flow-channel fracturing service uses locally sourced sand with the HiWAY flow-channel fracturing technique. Replacing a large percentage of the usual ceramic proppant with local sand further increased the cost efficiencies provided by the plug-and-perf system. The degradable balls and seats of the plug-and-perf system eliminated milling runs. The HiWAY technique creates open pathways inside the fracture, enabling hydrocarbons to flow through stable channels instead of through proppant, resulting in infinite fracture conductivity and higher production. At the same time, proppant and water usage are reduced.

Integrated system more than halves stimulation time and delivers superior production

Pumpdown operations proceeded smoothly and 16 stages were successfully stimulated in 4.5 days with no premature screenout. This integrated system outperformed a third-party alternative used on another well for comparison (3.6 stages/day vs. 1.7 stages/day, respectively). Also, the Salik service enabled replacement of 80% of the ceramic proppant with sand, reducing costs a further USD 95,000.

A CT run after 7 days confirmed the dissolution of the plug-and-perf system seats, eliminating CT milling runs. The improved flowback ratio (21.4%) in the early days confirmed enhanced fracture conductivity and the superior production potential of this newly treated well.