Wang Anhui, Yu Shuying, Zhang Yingkui, et al. Application of neural network in well test analysis in low permeability oilfield[J]. 2004, 25(3): 338-343.DOI: 10.11743/ogg20040320.
"A" oilfield is a typical low permeability sandstone oil reservoir that has relatively successfully been developed in Jilin oilfield area.The well test interpretation is relatively complicated.The times of radial flow occurring on wells'pressure build-up curves account for only 20%~30% of the total times occurring in all tested wells.This paper introduces an integrated interpretation technology by integrating pattern recognition
neural network BP algorithm and well test interpretation software.It can specifically divided into the following steps:(1)analyze and interprete the bilogarithmic and semilogarithmic diagrams of wells with radial flows
and find out the pseudoslopes(m
1
m
2
m
3
and m)in the continuous flow section
at the flex point
in the transitional section and on the straight line section of radial flow;(2)applying the neural network BP algorithm to construct the mathematical relation among m
1
m
2
m
3
and m;(3)input the basic testing data of the wells without radial flow into the well test interpretation software
derive the m
1
m
2
and m
3
and then derive m with BP algorithm;(4)substitute the parameters mentioned above and fitting them through to the three curves in the bilogarithmic and semilogarithmic diagrams
and in historic fitting diagram to be fitting to one another.