Abstract: Effective control of the chemical costs will significantly promote single well economic returns in Daniudi Gas Field. To solve the current problems like unclear cost control subject and lack of economic margin of single well chemical injection, we establish an evaluation model of the single well economic returns. And by comparing the running cost,the operation cost and the total cost of gas production volume with after-tax gas price,we divide single well production into four stages:operation with high return,operation with low return,operation with marginal profit,and operation with no return,and thus clearly define the subjects of cost control. Then through break-even analysis,we calculate the boundary value of chemical injection at different production stages,which provides reference for methanol and foam scrubbing agent in production. Application of the calculation can effectively control single well chemical cost and therefore promote the economic returns.

Key words: chemical cost, gas well, break-even analysis, injection volume of methanol, economic return