Progress in deep shale gas engineering technology in Weirong gas field in southern Sichuan

Abstract

Weirong gas field is the first deep shale gas field in China, with the characteristics of "deep burial depth, thin high-quality reservoirs, high ground stress, high horizontal stress difference, high plasticity and high formation pressure". The engineering technologies of drilling, completion, fracturing, and drainage face challenges such as long drilling cycles, small renovation volumes, low complexity, and complex wellbore flow laws. In response to complex geological challenges, we continuously enhance geological understanding, deeply integrate gas reservoir geology and engineering technology, and continue to research the drilling and production engineering technology with the goal of reducing costs and increasing efficiency and breaking through the benefits of deep shale gas. After three rounds of exploration and optimization of drilling technology, we strengthen and improve mechanical drilling speed, reduce downhole complexity, and shorten drilling cycles. The optimization of fracture configuration in fracturing technology has increased the breadth of complex fractures, and the integration of large displacement expansion and high sand carrying has achieved the increase and support of fracture control volume. The drainage process is based on gas-liquid two-phase flow research to identify wellbore flow patterns, forming a decision-making method for the entire lifecycle drainage process. Finally, an engineering technology sequence focusing on "fine trajectory control for optimal and fast drilling", "balanced expansion of fractures for strong support fracturing", and "full cycle effective drainage" was formed, continuously promoting the process of benefit deve-lopment. With the deep shale gas development engineering technology proposed herein, an accumulated new production capacity of 2.5 billion cubic meters in Weirong gas field has been completed, providing valuable experience for deep shale gas engineering technology at home and abroad, as well as a direction for further exploration and research in ultra-deep shale gas development.

Keywords

• deep shale gas
• engineering technology
• increasing drilling speed
• fracturing to increase production
• full cycle drainage gas recovery
• weirong gas field
• southern sichuan