The Key Engineering Techniques of the Wen 23 Underground Gas Storage

The Wen 23 underground gas storage area is the largest one in the central and eastern China. It has faced several challenges in its construction phase, such as difficulty in cementing, serious leakage, difficulty in evaluating the wellbore sealing, high requirements on the injection/production pipe string and the complicated conditions of existing well. To optimize operations, technical studies were conducted on the aspects of salt formation cementing, ultra-low pressure reservoir leakage-prevention and protection, wellbore sealing evaluation, injection/production and completion string design, and existing wells plugging and evaluation, and major technical difficulties during the construction of Wen 23 gas storage reservoir are solved. The key engineering techniques applied in the Wen 23 underground gas storage, the cementing quality has been significantly improved, the loss of drilling fluid has been reduced by 52.3%, and the wellbore sealing evaluation has improved the efficiency of construction decision-making. The construction of Wen 23 underground gas storage demonstration project provides technical supports and demonstration for the construction of similar projects.