Integrated Acid Fracturing and Completion Technology for Carbonate Reservoirs in Sichuan-Chongqing Area

Carbonate reservoirs in Sichuan and Chongqing are characterized by deep burial depth (>4500 m), high formation temperature (>130 ℃), multiple layers, low porosity, low permeability, and high sulfur content, How to deeply modify reservoirs and reduce costs is the most prominent issue faced by current exploration. Based on the wellbore integrity evaluation design, different degree of cloud, geological requirements, and acid fracturing design of the reservoirs in the Sichuan-Chongqing gas province, establish different acid fracturing completion process strings. The integrated process of single stage acid fracturing and completion is adopted for strong micatization,and the integrated process of multi stage fracturing and completion is adopted for weak micatization. This process can meet the requirements of temperature resistance of 160 ℃, pressure difference of 90 MPa, and long-term resistance to H2S and CO2 corrosion, Field tests were conducted in Well X, and the production was tested after the transformation, resulting in a gas production of 96.91 × 104m3/d, The technical goal of stimulation and reconstruction of this well has been achieved, providing technical support for exploration and development in Sichuan-Chongqing gas province.