A downhole automatic connection device for an oil pipe internal communication cable for intelligent layered water injection, comprising a water injection pipe string, and a hydraulic anchor, a cable-through packer, an intelligent water distributor, a hydraulic support anchor and a plug, the hydraulic anchor, the cable-through packer, the intelligent water distributor, the hydraulic support anchor and the plug are sequentially connected to a lower end of the water injection pipe string, wherein a cable lowering mechanism is arranged in the water injection pipe string;
- the cable lowering mechanism comprises a cable, a cable female connector, a motor and a plurality of load-bearing blades;
- a tail end of the cable is sleeved with a housing;
- the plurality of load-bearing blades are uniformly hinged on a cylindrical surface of the housing in a circumferential direction of the cylindrical surface;
- a roller is rotatably mounted at an end of each of the plurality of load-bearing blades;
- each roller is tangential to an inner wall of the water injection pipe string;
- a through groove which is positioned above each of the plurality of load-bearing blades is arranged on each of two sides of the housing;
- the housing is sleeved with a left semicircular member and a right semicircular member, the left semicircular member and the right semicircular member are fixedly connected;
- a first connecting rod is hinged on the left semicircular member and the right semicircular member;
- an end of the first connecting rod is hinged on each of the plurality of load-bearing blades;
- two second connecting rods penetrating through the corresponding through groove are respectively fixedly arranged on the left semicircular member and the right semicircular member respectively;
- a nut is fixed between the two second connecting rods;
- the motor is fixedly arranged in the housing;
- a screw rod is connected to an output shaft of the motor and is in a threaded connection with the nut;
- the cable female connector comprises a female connector shell a jack insulating plate and an electromagnet;
- the female connector shell is fixedly arranged at a bottom of the housing and communicated with the housing;
- the electromagnet is arranged at a bottom of the jack insulating plate;
- the jack insulating plate is fixedly arranged on the female connector shell;
- an annular groove is arranged between the jack insulating plate and an inner wall of the female connector a bottom surface of the female connector shell is a guide surface inclined to left;
- a right cylindrical surface of the female connector shell is provided with a guide groove;
- the jack insulating plate is internally provided with a jack that is arranged vertically;
- a jack wire welding point is fixedly arranged on a top of the jack;
- a conductive sleeve is arranged in the jack and is fixedly connected with a first end of the jack wire welding point;
- a second end of the jack wire welding point is connected with the cable;
- a cable male connector is fixedly arranged in the water injection pipe string;
- the cable male connector comprises a male connector shell a pin insulating plate and an NdFeB magnet;
- the pin insulating plate is fixedly arranged in the male connector shell;
- the NdFeB magnet is arranged on a top of the pin insulating plate;
- a tapered surface matched with the guide surface is arranged in a middle of the male connector shell a right cylindrical surface of the pin insulating plate is provided with a guide bolt matched with the guide groove;
- a pin and a pin wire welding point are arranged on a top and a bottom of the pin insulating plate respectively;
- the pin wire welding point is electrically connected with a sensor on the intelligent water distributor;
- a lead which is positioned in the pin insulating plate is connected between the pin (35) and the pin wire welding point.