Combination of economic factors with technological factors can boost the economic value of the reserves and make the marginal reserves tum into the recoverable reserves.

With the development of national economy and increase in demend for petroleum resources, the evaluaion ofmarginal reserves has become more and more important.

Through the combination of gray system theory and the characteristics of marginal reserves, the paper describes the multistage comprehensive gray estimate method, which makes the quality of marginal reserves be quantitative.

Because change plots tone, which is detected automatically by dynamic monitoring of Land use, distributes in a definite range, in order to extract change information efficiently, change plot and its surroundings are bi-valued using technology of image processing of Photoshop, and vector boundary of change plot is drawn automaticaly by vector arithmetic of similar four directions in this paper.

Unidirectional Amplification Theory and Its Technical Processing for Permissible Errors of Measured Boundary;