THE CURVE FITTING ALGORITHM FOR THERMAL DESORPTION OF SHALE GAS.

Shale gas is a kind of very important unconventional oil and gas resource, which exists in the form of adsorbed gas and free gas in shale. Shale gas content is the key factor for shale gas assessment and core area evaluation. Desorption method is an useful method of shale gas content measurement, but the disadvantage of this method is that the test course takes a long time. We have done some shale gas desorption experiments in Chinese northern Shanxi and put forward five fitting algorithm models. By analysing correlation coefficient and the characteristic of desorption rate, it is found that composite function fitting can correctly reflect the desorption process, in the meantime, according to the graphical method of measured data, it is revealed that there is a clear positive correlation between desorption rate and desorption temperature. The research results are useful for predicting shale gas content and greatly reducing the testing time of shale gas desorption. [ABSTRACT FROM AUTHOR]