High‑yield Well Sets New Buried‑hill Drilling Record at Bozhong 19‑6 Condensate Gas Field in Bohai Bay

According to China National Offshore Oil Corporation official releases, a development well at the Bozhong 19‑6 condensate gas field recorded strong hydrocarbon flow on 1 September within the Bohai Oilfield. The well delivers daily gas output exceeding 210 000 cubic metres alongside nearly 400 cubic metres of crude oil per day, outperforming its planned production targets. Its total drilled depth surpasses 6 300 metres, establishing a new depth benchmark for buried‑hill well construction across the Bohai Oilfield.

Classified as an ultra‑deep development well, the borehole requires roughly 700 connected drill pipes to reach its final target depth. Down‑hole operating conditions place severe mechanical stress on drilling assemblies; drilling torque rises by approximately 40 per cent compared with conventional offshore operations and approaches the performance limits of available drill‑string hardware. High‑temperature, high‑pressure complex formations narrow the usable operational window for field crews. Drill bits travelling through deep submarine strata carry persistent risk of trajectory deviation, demanding real‑time geological judgement and precise directional adjustments to intercept productive reservoir zones.

During drilling operations, technical teams under the Tianjin‑based project division continuously upgraded buried‑hill drilling workflows and refined operational protocols. A complete technical and management framework was put in place covering pre‑drill risk assessment, real‑time down‑hole intervention and emergency response for complex subsurface events. Big‑data‑powered while‑drilling monitoring identifies high‑risk geological boundaries in advance and triggers targeted mitigation measures. Dynamic adjustments to drilling‑fluid properties, finely tuned drilling parameters, friction‑reduction tools and enhanced hole‑cleaning procedures maintain drill‑string integrity and enable steady penetration towards target reservoir horizons.

Integrated engineering‑geology collaboration underpins both operational safety and productive capacity. Technical systems for lost‑circulation prevention, reservoir protection and rate‑of‑penetration improvement undergo iterative optimisation. Completion designs are revised to enable temporary well sealing during completion work phases. This safeguards subsurface reservoir properties and unlocks the full productive potential of the hydrocarbon bearing formations.

Further well‑site evaluation and commissioning work will proceed for this ultra‑deep well. Technical learnings drawn from this high‑yield borehole will feed into subsequent buried‑hill development programmes across the wider Bohai basin, supporting future deep‑stratum hydrocarbon extraction activities.