The deep, tight gas reservoir in the Daqing oil field, P. R. China has multiple parallel sandy conglomerates with horizontal heterogeneity and poor historical production from vertical wells and single-lateral horizontal wells. These blocks comprise a large volcanic gas reservoir, which is also challenging for directional drilling. This paper describes a dual-lateral completion with hydraulic fracturing that addresses these production issues.
To deploy a stacked dual-lateral well in this reservoir, the deep well depth and its high temperature are considered. The junction must be sealed because of the borehole stability and gas. Re-entry to both laterals, temporarily isolation of laterals, openhole multi-stage hydraulic fracturing and commingled production was possible with a multilateral completion system. This was the operator's first installation of this technology.
As a result of comprehensive study, the TAML Level 4 Hook Hanger Multilateral System and One-trip Open Hole Multi-stage Frac System were selected. The junction was successfully cemented after installation of the Hook Hanger System. Each lateral was installed with more than 10 stages of frac system completion tools. After both laterals were hydraulically frac and flow tested, the commingled upper completion string was installed for commercial production.
The application of multilateral technology in this field was completed safely. Gas production rates from the multilateral well tested 4.3 times greater than the average production rate from the three offset vertical wells. The absolute open flow rate achieved was more than 1MMSCM, which is the biggest producer for tight gas reservoir in Daqing area. This production rate indicated that the dual-lateral well fracture completion method was applicable for this reservoir.