Water exploration method and device for perforated casing completion horizontal well

The invention provides a water exploration method and device for a perforated casing completion horizontal well. The water exploration method for the perforated casing completion horizontal well comprises the following steps of S1, placing a water exploration device for the perforated casing completion horizontal well in a horizontal well; S2, starting an oil-well pump, and detecting and recordingwater content data of current oil liquor; S3, starting a pressurizing device, conveying a ball valve of the water exploration device for the perforated casing completion horizontal well to the Nth water exploration valve of the water exploration device for the perforated casing completion horizontal well to block a by-pass flow channel of the Nth water exploration valve, wherein the valve ball passes through the Nth water exploration valve, and N is a positive integer; and S4, starting the oil-well pump again and detecting and recording the water content data of current oil liquor, and repeating the steps S3 and S4,