Small well spacing tests were carried out in three and four zones of the transitional zone to solve the problems of poor effect of water flooding and low reserves utilization. In order to improve the effect of water drive development in the transitional zone of Area A, the two test zones in area a have been reopened and utilized, well pattern is changed from anti-nine-point method to five-point method. Through strengthening the tracking adjustment of oil and water wells, the variation law of production and water cut in the test well area with small well spacing in the development process is understood, and the adaptability of different well patterns and well spacing in three or four zones is verified, it provides a technical reference for the adaptability of water injection in three or four zones of the transition zone.