Method for implementing six-stage multilateral well completion by posterior inferior three-way branching mechanism

The invention provides a method for implementing six-stage multilateral well completion by a posterior inferior three-way branching mechanism for completion of oil, gas and water well drills of an oil field, which is implemented through a six-stage multilateral well completion system and a predeformed three-way branching mechanism. The six-stage multilateral well completion system consists of an intermediate casing, a hollow slope guide device, an external annulus sealing member of the slope guide device, a suspension positioning orientator, an upper sealing member of a branching mechanism of an annulus sealing member of the positioning orientator, the branching mechanism, a lower sealing member of the branching mechanism, a completion string of the multilateral well, a main well bore cylinder, a conductor and a branching well bore cylinder of the branching mechanism. The method is characterized in that after the branching well bore drill is completed, the predeformed three-way branching ...

Floatingly-hinged rolling variable-diameter expansion drill bit

The invention discloses a floatingly-hinged rolling variable-diameter expansion drill bit for use in petroleum drilling, well repair and well completion operation, which comprises a body, a fixed shaft, a supporting shaft, a tapered roller, a floating shaft, a floating wedge block, a piston, a driving drill bit block, a spring, a hydraulic cylinder, a sealing ring and a guide shoe, wherein the body is in threaded connection with a feeding drill; the lower part of the body is in threaded connection with the guide shoe or a lower tool; a variable-diameter expansion part consisting of the supporting shaft, the tapered roller and the floating wedge block is embedded in the radial groove in the body; one end of the supporting shaft is hinged with the body by the fixed shaft; the supporting shaft radially swings around the fixed shaft; the other end of the supporting shaft is in hinged connection with the floating wedge block through the floating shaft; the piston and the driving drill bit block ...

Linear displacement detecting method

The invention relates to a linear displacement detecting method for detecting the linear sliding displacement of a down-hole string in an oil field. The method is designed by taking a hall element as core and is used for detecting the linear displacement by an oscillating mechanical contact roller displacement measuring device; relative rectilinear motion of two objects is converted into the rotating of a roller, and the displacement is calculated by measuring the rotating angle and direction of the roller; the detecting device consists of a contact face, a fixed support, a swing stem, a spring, a hall element, a magnetic cylinder and the roller. The signal detection processing system of the displacement detecting method consists of the hall element, a signal adjusting circuit, a single chip, a memory, a clock circuit and a communication display module. The computing formula of the displacement is S=PiD/n*C, wherein, S is immediate transformation at one moment, D is the diameter of the ...

Method for implementing branch well window seal by using metal expansion tube

The invention relates to a method for realizing window sealing of a multilateral well by utilization of a metallic expansion tube, which is used for completion window sealing of an oil gas well. The method is mainly realized through a window sealing structure of the multilateral well, a positioning and orienting feeding device and a running system of a branched metallic expansion tube. The method comprises the following steps: firstly, drilling of a main wellbore is completed by the drilling method of the multilateral well, and a main wellbore pipe column is run into the ground; and secondly, a whipstock is run into a designed windowing position, drilling of a branched wellbore is completed through side tracking windowing, a completion pipe column of the branched wellbore is hung on the upper part of a hollow wedge deflection tool through a pre-opening suspension device, a predeformed branched sealer is run into the window position by utilization of the feeding device, and shape recovery ...

Rotary variable-diameter expansion device

The invention provides a rotary variable-diameter expansion device for the operations of petroleum drilling, well repair and well completion, which consists of an upper joint, a central pipe, a fixed seat, a fixing nail, an annular spring, an expansion block, a driving piercer, a shearing nail, a backing-up screw, a hydraulic cylinder sleeve, a piston, a return spring, an outer sealing ring of the piston, an inner sealing ring of the piston and a hydraulic cylinder end sealing ring, wherein the upper end of the upper joint is in threaded connection with a fed pulling pipe column while the lower end thereof is in threaded connection with a central pipe; the two ends of the central pipe are external threads, and the lower end thereof is connected with a guide shoe or an expansion pressure limiting valve; the upper part of the central pipe is provided with two projecting steps; an upper step is provided with a T-shaped guide positioning groove matched with the fixed seat; the lower part of ...

Branched selective reentry method and apparatus

Branch well window sealing method

The invention discloses a branch well window sealing method for sealing branch well windows of oil and water wells. The method is implemented through a sealing device; the device consists of a main borehole under the window, a branch borehole and a main borehole above the window; the sealing device is made of a material which has certain elasticity, can expand and can recover deformation, and the sealing device is molded by die casting or tube welding; after the sealing device and a running tool are dropped to the branch well window, the sealing device is firstly expanded by hydraulic pressure, and simultaneously a drilling tool is dropped to make the sealing device descend till to the designed position; after the sealing device is completely expanded, a feeding pipe column is pressed down to shear a connecting dowel between the running tool and the sealing device so that the running tool and the sealing device are separated; the feeding pipe column and the running tool are extracted from ...

Bushing button bit and machining method thereof

The invention provides a bushing button bit and a machining method of the bushing button bit and relates to drill bits used in various drilling projects. The bushing button bit comprises teeth arranged on a bit body. The teeth are inlaid and fixed into tooth holes in the bit body through tooth roots. The bushing button bit is characterized in that the diameter of an orifice of each tooth hole is smaller than the maximum diameter in the tooth hole; the diameter of the part, matched with the orifice, of the tooth root of each tooth is smaller than the maximum diameter of the lower portion of the tooth root of the tooth; a bushing is arranged between each tooth and the corresponding tooth hole; the tooth roots of the teeth are inlaid and fixed into the corresponding bushings in an interference fit mode, and the bushings are inlaid and fixed into the corresponding tooth holes in an interference fit mode. Through the combining form of the teeth, the bushings and the tooth holes, falling teeth ...

Fish bone shaped lateral well drilling and completion technique

The invention relates to a technique method for the completion of fishbone branch well drilling. The technique method comprises the following steps: after an uncased hole hanger and a tail pipe are put down after the completion of a main well bore, a plurality of branch window whipstocks and windowing tools are put down one by one; each branch well bore is drilled respectively, the uncased hole hanger and a completion pipe column are put down to complete drilling and finally the tail pipe is suspended at a technical bushing through a hanging-up packer in pipe. The method has the advantages that: the reducing of the size of the main well bore of the fishbone branch well completed by the method, which is caused by the branch well bore does not occur, the number of the branch well bore is not limited and the bare area of the oil coat can be increased to the greatest extent. The method can drill fishbone branch wells at any type of oil coat, and cold production and thermal production can be ...

Rotatable wellhead connection device

The invention relates to the technical field of expansion pipes, particularly to a rotatable wellhead connection device which is applied to the long well segment expansion pipe construction. An outer cylinder is inserted into the lower end of an upper joint of the rotatable wellhead connection device; a gland sleeves the upper joint and is connected with the upper end of the outer cylinder through an upper fastening bolt; the side wall of the lower portion of the upper joint is designed into a protruding step surface; the lateral side of steps of the upper joint and the inner wall of the outer cylinder are sealed through a v-shaped sealing ring; the upper end of the steps of the upper joint is designed into a conical surface; a conical surface which is matched with the conical surface formed on the steps of the upper joint is designed on the inner wall of the outer cylinder. According to the rotatable wellhead connection device, the rotation of a wellhead high pressure pump inlet pipeline ...

Underground branching device for multi-branch well

The invention discloses an underground branching device for a multi-branch well, which is used for sealing branch wells of an oil or water well in an oil field and consists of a main well casing, a main branch well transition section, a first branch well casing, a second branch well casing and a third branch well casing. The underground branching device for the multi-branch well is made from a pipe body made of an easily deformable high-strength metal material by welding or other methods. The device may be an underground branching device for a three-branch well, wherein the upper end of the device is provided with the main well casing; and the lower end of the device is provided with three branch well casings. And the device may be an underground branching device for a two-branch well with tapered and spherical transition section, wherein the upper part of the device is provided with the main well casing; and the lower end of the device is provided with two branch well casings. After the ...

Fish bone type branch well drilling and completing method