According to the association analysis method,we confirm many influence factors of economical indicesof the developed low-grade reservoirs and their related influence extent to the economical indices.By picking out theimportant influence factors and combining it with the superior experience of experts,we present an indices systemof the developed low-grade reservoirs.Considering this indices system,we make the important influence factorsconstraint condition of a profit model,and then the optimal model of maxi...