How to Meet 'Zero Discharge' Goal in a Sensitive N. Azadegan Field Wetland Environment?

摘要

North Azadegan field with more than 4,886MMSTB reserve to drill 58 wells in less than 3 years, operation area with average about 2.5m water depth, belongs to one of International Nature Reserve Conservation Zones faced with a huge environmental challenge. Traditionally onshore operations in Iran, water based drilling mud and its cuttings have been disposed of directly on the ground in unlined pits, because disposal of drilling wastes poses no serious threat to the environment. However, a Zero- discharge goal is required for this sensitive wetland of N.Azadegan field. This paper shares an overview of how to achieve a zero discharge goal in a remote, rural, sensitive wetland, accompanied with the below applicable methods:1)Cluster well pad design and construction including waste treatment layout; 2)Generic waste management stream for minimizing contamination; 3) Treatment of drilling cutting waste as pavage for other pads or road construction; 4)Reuse of waste water for mixing mud etc. While contractor?s waste management equipment and personnel daily rates add to the drilling operation cost of the project for higher cost ceiling under Buy-back contract, cutting treatment and mud reuse techniques actually reduce total N.Azadegan project cost, combined with careful planning, advanced equipment and services. This paper will report the past experiences and lessons of these waste management methods in N.Azadegan. In details, the waste treatment and management technologies integrated with well pad construction will be evaluated feasibly and economically.