In logging industry, the logging work is carried out after the work of drilling crew in different area and under different complex situations, because of the difference between the structure of the well body of artesian well and quality of well body, the different situations in the well bring many difficulties to logging work. Such as the accident of wall sticking of stick of the downhole logging instrument may often happen, it may result in significant economic losses to the unit if it can not be handled well.

With the continuous progress of science and technology, more and more advanced equipment are introduced into the well-logging industry, and they are very expensive, equipped with advanced fishing tools has become more important. In well-logging industry, the tools in free stick of downhole instrument are slip cylinder and three-ball fisher, fishing the downhole instruments with piercing fishing method. However, the piercing fisher has a fatal weakness:

I. The work should be carried out when the cable is cut off, so as to cause large economic loss.

II. The instrument and the stick free situation can not be observed directly, it is very difficult to construct.

III. There must be many people to draw the cable to pierce from the drill stem and connect while getting and changing the drill stem every time, the working strength is large.

How to solve the problem to fish the downhole instrument with out cutting the cable and conquer the shortcoming of the piercing fisher, we should solve the problem based on the situations of artesian well and logging work, and cooperate with the relative research institute and academic institution to research and develop the patented product produced by only one factory at home “side door continuous cable logging fisher”, so as to solve the fishing work of downhole sticky instrument cable which has puzzled the well-logging industry, so as to increase the working efficiency to save much money, so the economic benefit increases.

1. Structure

The side door continuous cable fisher is made up of oriented body, guide wheel, main body, spring, steel ball, guide shoe and locking block, referring to the drawing.

The main body cooperates with the three steel balls, and there is a lengthways channel for placing the cable. When the cable is placed in the fisher, put in each locking block, rotate each section to form the sealing annulus. There are connecting screw on the upper part of oriented body, it can be connected with oil pipe and drill stem.

2. Working Principles

The side door continuous cable fisher depends on the changing of the position in the inclined hole of the three steel balls to change the size of diameter of common inscribed circle of the three balls, so as to allow the elbow fishing bell of logging instrument to pass through. When the elbow enters the guide shoe, the fishing bell pushes the steel ball to rise along the inclined hole, while compressing the three supporting springs, when the fishing bell pass through three balls, three balls goes back along the inclined hole by its self weight and pressure of spring, the three steel balls in the inclined hole may provide chucking force to fishing bell in radial direction under the effect of inclined hole.

3. Using Methods

(1) The cable is supported on the rotating plate by the cable hanger (T-shaped pincers).

(2) Inserting the cable into the top and bottom pulleys, then the top pulley is fixed on the girder of the crown block or the other suitable position, and the bottom pulley is fixed on the suitable position of the drilling platform, the weight indicating gage is set on the lower end of the bottom pulley.

(3) The fisher is connected to the fishing drilling tool, the mounting and dismounting method of the fisher is as follows:

A. Dismounting:

a. Revolving the main body widdershins, taking down the locking block of oriented body after screwing it.

b. Taking down three plugs and springs from the main body with allen wrench to pour out the steel ball.  

c. Revolving the guiding shoe widdershins, taking down the locking block of guiding shoe after screwing it.

d. Taking down the locking block from the main body.

B. Mounting:

a. Placing the cable into the guiding shoe and main body, then mounting the corresponding locking blocks and screwing them.

b. Placing the steel ball, spring and plugs in the main body.

c. Placing the cable in the oriented body, mounting the locking block of oriented body on the oriented body, and then screwing with main body.

(4) Lifting the tensioning cable of winch for electric logging to fish the drilling tool, (the downhole hanging load of the cable of instrument is used as the standard) dismounting the cable hanger, checking if each part is suitable.

(5) Drilling down with the dual elevator, so the side of the elevator can guide the cable, it can lock the rotating plate and hook lockpin while drilling down, and the drilling tool can not revolve while drilling down. The speed for drilling down should be slow, monitoring the changing of the hanging load of the weight indicating gage of drilling tool and cable.

(6) Calculating the length of the pipe column and the sticky depth of instrument. When the drilling tool goes to the deep position, if the tensility of the cable increases, the fisher or the cable may be curved, it can be judged based on the natural potential or other well-logging curved line. If the drilling column goes to the depth of the instrument, but the tensility of the cable does not increase, the reason may be the error of the length of the column drilled down, the downhole cable in deep well and the drilling tool has may differences; or it is caused by the elongation of the cable, so the depth must be corrected carefully.

(7) the column and cable can be drawn up after fishing the instrument.

(8) The steps of dismounting the fished goods on the ground:

a. Revolve the oriented body widdershins until screwing down the oriented body, then taking down the locking block of oriented body.

b. Taking down three plugs and springs from the main body with allen wrench to pour out the steel ball.

c.Taking out the elbow head

4. Technical specification

Technical Specification of Side Door Continuous Cable Fisher

Remarks: the fisher of instruments of different model can be processed according to the requirement of user