Development of Large-Scale Tight Gas Sandstone Reservoirs and Recommendations for Stable Production-The Example of the Sulige Gas Field in the Ordos Basin

The natural gas reserves and gas recovery rate of tight gas sandstone reservoirs in the Sulige gas field in the Ordos Basin play a crucial role in China's natural gas industry. This study aims to enhance the stable production time of the gas field by summarizing the geological characteristics of the tight gas sandstone reservoirs in the Sulige gas field, discussing the challenges in the development of the gas field, and providing recommendations for the development of the reservoirs. The results show that the matrix reservoir properties, effective sand body size, and gas-bearing properties of tight sandstone gas reservoirs in the Sulige gas field exhibit strong heterogeneity characteristics, and the western and northern parts of the basin edge are gas-water mixed storage areas. There are obvious differences in gas well production, cumulative production, production decline rate, and single well dynamic control reserves in different regions. The recovery of gas reservoirs is primarily influenced by reservoir quality and development well pattern. Increasing the well density increases from 1.5/km(2) to 4/km(2) in the gas field enrichment area, can raise the corresponding recovery rate from 26.0% to about 50% under the existing economic and technical conditions. Therefore, ensuring a stable production of the tight gas sandstone reservoirs in this gas field is challenging. To achieve a long-term stable production of the gas field, it is necessary to promote the refined reservoir description technology and improve the production through various measures such as replenishing fractures in wells with depleted fractures, sidetracking horizontal wells, and re-fracturing, thereby improving the reserve utilization degree. Moreover, implementing the negative pressure gas recovery technology as soon as possible can restore the production capacity of near-depletion wells.

Automated summary

The geological characteristics of tight gas sandstone reservoirs in the Sulige gas field in the Ordos Basin are summarized, and the challenges and recommendations for the development of the reservoirs are discussed in order to enhance the stable production time of the gas field. The results show that the reservoir properties of tight sandstone gas reservoirs in the Sulige gas field exhibit strong heterogeneity, and increasing the well density in the enrichment area can significantly improve the recovery rate. To achieve long-term stable production, it is necessary to improve the reservoir description technology and implement measures such as replenishing fractures, sidetracking horizontal wells, and re-fracturing.