Abstract
In the future, there will be more and more abandoned oil-gas wells with the exploitation of onshore oilfield resources. However, the large height difference in abandoned oil-gas wells can be used as building blocks for gravity power generation, thus maximizing the economic value of abandoned oil-gas wells. In this study, a scheme of gravity power generation by virtue of the spud-in casing depth of oil-gas wells is proposed, and a gravity power generation model based on abandoned oil-gas wells is established. The parameters and economic benefits of gravity energy storage are calculated for oil-gas wells in the Huabei oilfield, the Daqing oilfield, and the Xinjiang oilfield. It is shown that the power density and discharge time of the gravity energy storage system in abandoned oil-gas wells are suitable for distributed power generation. In addition, the fast response characteristics of energy storage in abandoned oil-gas wells are verified, which makes the system suitable for correcting continuous and sudden frequency and voltage changes in the power grid but not suitable for energy arbitrage under a high number of annual cycles. Furthermore, the leveling cost of storage of the gravity system in abandoned oil-gas wells is more economical with the high number of annual cycles. The analysis of this work provides a significant investigation of the feasibility of gravity power generation by using abandoned oil-gas wells.