Estimation on the economic life of long-distance oil and gas pipelines

Service life of oil and gas pipeline is divided into design life, physical life and economic life according to their purposes. The methods on estimating the economic life include the minimum annual cost method and expense-benefit method. The expense-benefit method includes the maximum annual profits method and the total income analysis method. The minimum annual cost method is mainly applied to the cost center and human profits center, which has stable income or takes the cost control as its income subject to the prior plan. According to the operator's tolerance level and preferences, the expense-benefit method mainly provides different reference age limit for the economic operation from the perspective of operating efficiency. In consideration of the time value, this article selects actual data from a pipeline of Northeast pipeline networks to evaluate its economic life from the perspectives of the whole life cycle and the remaining life cycle, using the minimum annual costs method and maximum annual profit method, and assessment results with useful reference value are obtained.