Exploration and Practice of Composite Acid Fracturing Technology for Ultra Deep Bedrock Reservoirs in the Qaidam Basin

The Kun2 block bedrock gas reservoir of Kunteyi gas field is located in the Qaidam Basin, with a burial depth of over 7000 m. The reservoir space is composed of fractures and matrix pores, with many high angle and high conductivity fractures. It has the characteristics of high pressure, ultra-high temperature, high horizontal stress, and large reservoir span. Due to the unfavorable conditions of the reservoir, the block measures for transformation and production capacity release are limited, and the difficulty of benefit development is high. In order to explore the development methods of block benefits, with the main goal of process safety control and fully improving production through transformation, a set of composite acid pressure transformation technologies suitable for ultra deep bedrock reservoirs has been developed through research on geological engineering integrated reservoir classification, composite acid pressure demonstration, integrated well completion pipe safety verification, and combined temporary plugging technology. Through practical application, good production improvement effects have been achieved, realizing the full transformation of ultra deep bedrock reservoirs and the effective utilization of multiple layers. This process technology has taken a crucial step towards exploring the benefits of block development and provides technical references for similar block transformation methods.