For the oilfield developed with water injection, the Honor method and the MDH
method cannot be used to obtain the average formation pressure of the injectionproduction well group. Based on the well test data, the MDH and Y
function method was first used to obtain the formation pressure of the injectionproduction well. Then, according to the principle of potential
superposition, the formation pressure between the injectionproduction wells was calculated. Finally, the average formation pressure of the
injectionproduction well group was obtained by combining the pressure drop rate and the resistance weighted average method, and the formation
pressure contour of the injectionproduction well group was established. Using this method, the average formation pressure of the L10718X Well
group of the Liu107 fault block in Dawangzhuang Oilfield was obtained, and the value was 2923 MPa. The pressure distribution contour of the well
group shows that the injection water velocity was the fastest along the direction of L10713 Well and the slowest along the direction of L107
17X Well group. This conclusion was consistent with the tracer monitoring results. The method can obtain reliable average formation pressure of
injectionproduction well group, evaluate the effect of water flooding development, and provide scientific basis for adjustment and design of
development plan in waterinjection development oilfield