Evaluating the oil production and wastewater treatment efficiency by an extended two-stage network structure model with feedback variables.

Oil is an indispensable and important energy source in modern society, and oil production plays a vital role in economic development. However, there is no denying that oil production has a very bad impact on the environment. To realize the sustainable development of oil production, the environmental problems caused by oil production need to be controlled and managed strictly. Aiming at the practical problems of insufficient recoverable reserves of high quality oil and aggravating environmental pollution, efficient oil production and wastewater treatment become more and more important. Therefore, the whole system is divided into two stages. The stage 1 is oil development, and the stage 2 is wastewater treatment. Considering that the model needs to solve the undesirable output, an extended two-stage Slacks-Based Measure (SBM) Data Envelopment Analysis (DEA) network structure model with a feedback variable is established. The efficiency value of each stage can be obtained, and the weakness of each stage can be identified, so that the efficiency value of the whole system is more accurate. And then thirteen oilfields are selected for the numerical analysis to verify the validity and accuracy of the proposed model, the results demonstrate that the overall system is efficient only if the two stages are efficient; the oil production has higher efficiencies than the oilfield wastewater treatment; There is a stronger relationship between the efficiency of oilfield wastewater treatment and the whole system. A comparison with a traditional model demonstrated that the proposed model has a more scientific, stable and practical evaluation methods.