Fishing operations are understood as a set of operations necessary to free the wellbore from foreign objects before drilling is resumed in it.
Fishing tool. For fishing operations, special (fishing) tools of various types and purposes are used. Let's dwell on the main ones.
The taps are designed to catch the drill pipe string remaining in the well if a break occurs in the thickened part of the pipe, in the lock or coupling. The right taps are used to extract the entire string, and the left taps (on the left drill pipes) are used to extract the string in parts.
The fishing tap has the shape of a truncated cone for cutting into the details of the lock of drill pipes during fishing operations. At the upper end of the tap, a drill pipe lock thread is cut, and at the lower end - a special fishing thread (right or left).
The bells are used to catch drill or casing pipes when a break occurs in the body of the pipe, as well as when the threaded connections of the pipe are broken, except for cases when the thread is broken from the side of the lock nipple.
If the breakage is uneven with bands or there is a crack along the pipe that is not covered by the bell, then for fishing it is necessary to use a “through” (open) bell with an appropriate branch pipe or pipe. To extract the bit remaining in the well due to unscrewing or stripping of the thread, a bell-caliber is used.
The right bells are used when catching the entire remaining string with the right drill pipes, and the left bells are used when catching with the left drill pipes to unscrew part of the left string.
Bells are made from forged blanks, in the upper part of which threads are cut to attach to drill pipes. In the lower part of the bell, an internal fishing thread of a special profile is cut to grip drill pipes during fishing operations.
When the end of the drill pipe remaining in the well turned out to be uneven as a result of breaking and there are longitudinal cracks, then a “through” (open) slip with an appropriate branch pipe or pipe is used to catch the first from the broken end of the coupling or for the whole part of the pipe. The slip allows the well to be flushed through the trapped drill string. If the rest of the column cannot be lifted, the slip can be released.
The overshot is used to extract the drill string with a locking grip. It is used mainly where the catcher cannot be used, and the bell and tap cannot be connected to the remaining part of the drill string at the bottom, and where the length of the string does not exceed 400 m and it is not stuck.
An overshot is a body made of a thick-walled, usually shoe-type tube, inside of which four steel springs are riveted. The upper ends of the springs are bent according to the size of the drill pipes for which the overshot is intended.
An external pipe cutter is used in cases where it is not possible to release a stuck drill string using oil, water, acid baths or by torpedoing and the pipes remaining in the well are not bent.
A fishing rod (“ruff”) is used to retrieve the steel rope and logging cable left in the well. A fishing rod is made by welding hooks onto a rod or a tap in a checkerboard pattern, or from a casing pipe, on the body of which cuts are made that bend inward. It is forbidden to lower a fishing rod (“ruff”) into the well without a special clamp that limits the passage of this tool to the area where the abandoned rope or cable is located.
Withdrawal hooks are designed to center the end of the drill pipe remaining in the well.
The diameter (outer) of the hook mouth is usually 52 - 50 mm less than the diameter of the well. On the inner surface of the throat of the hook, before descending into the well, notches are made, according to the workability of which they judge (after lifting) how the hook worked, whether it touched the column or not. It is allowed to use a retractable hook only when it freely reaches the “head” of the break.
The milling cutter is used for partial or complete removal of metal protruding parts or parts. The work of a milling cutter (milling) consists in the destruction of a metal object and turning it into chips. The external shape of the router depends on its purpose:
- a) frontal action: flat; conical; and cylindrical;
- b) external influence: in the form of a truncated cone, conical, cylindrical and cylindrical-conical.
- c) internal impact: cylindrical-conical shape and combined impact.
Fishing tools:
a - slips; b - bell; c - tap; g - magnetic milling cutter; d - spider
Elimination of accidents with drill pipes and bits
Successful recovery of drill pipe accidents depends to a large extent on how soon the moment of pipe breakage is noticed.
When accidents with drill pipes are detected, the driller lifts them from maximum speed. The raised end of the broken part of the drill string at the surface is cleaned, washed and inspected to ascertain the nature of the break. Then, the number of candles remaining in the well is counted, the depth at which the upper end of the broken pipe string is located is determined, and measures are planned to eliminate the accident.
Work to eliminate an accident (any) in a well is carried out by a drilling foreman under the guidance of a senior engineer (foreman) for complex work or a chief (senior) engineer of a drilling enterprise (exploration, site), depending on the complexity of the work.
Before lowering the fishing tool into the well, a sketch of its general layout and fishing part is drawn up, indicating the main dimensions. To catch the drill string, a catcher (slip) with flushing, a tap or a bell is used. These tools make it possible to reciprocate and clean out the well after grabbing the remaining drill string. The length of the fishing tool lowered into the well should be selected in such a way that the fishing tool is fastened by a rotor with a leading drill string passed through the rotor table.
The catcher (slips) is used both for catching by the lock and by the pipe. To extract the string with a catcher, they give a stretch, turn on the mud pump, restore circulation, and then begin to lift it. If the column does not rise, it is walked around without rotation.
The tap is usually run with a larger diameter guide tube ending in a funnel. The tap, lowered on the drill pipes, covers the torn end of the pipe with a funnel and enters the inside of the pipe with a cone until it rests against the edge of the pipe. Raising the drill string a little to relieve pressure on the broken end of the pipe, turn it clockwise by 90 °, then back by 45 ° and again by "/4 turns clockwise. When the drill string is gradually lowered down, the tap cuts into the pipes and is fixed in them. It is forbidden to finally fix the fishing tool on the scrap until the circulation of the drilling fluid through the bit is restored. After that, they try to raise the string. In case of sticking, they walk around. If the circulation cannot be restored, the tap under tension is torn off.
Similarly to the one described, work is underway to connect and extract the remaining column with the help of a bell.
With a strong deviation of the end of the string from the center of the well, it is taken to the center by means of a withdrawal hook, and only after that a tap or a bell is lowered.
When, even after the restoration of circulation, it is not possible to free the column by pacing, resort to an oil bath or take other measures. If all attempts to release the tool are unsuccessful, they proceed to unscrew it in parts with the left tap or bell on the left pipes. Sometimes, instead of unscrewing in parts, the milled part of the remaining tool is cut out using an external pipe cutter. In this case, the cut off part is removed from the well along with the pipe cutter.
The main tool for extracting bit parts remaining in the well is a magnetic milling cutter, which is lowered into the well on drill pipes. Not reaching the bottom of 6 - 7 m, flushing begins, rotating the rotor at low speed. Having reached the face, with a small axial load, the milling cutter collects the remaining parts in the center of the face, the magnetic milling cutter bit is drilled into the rock, the lower pole approaches the parts remaining on the face and holds them. Then flushing stops and the rise of the drill string begins. In no case should you work on the remaining metal parts for a long time - this in most cases leads to a complication of the accident. A magnetic milling cutter is also used to catch all kinds of small metal objects that have fallen into the well.
fishing tool
(a. catching tool; n. Fanggerat, Fangwerkzeuge; f. outil de repechage, attrapeur, attrapetout; and. arpon pescatubos) - devices and mechanisms used to extract a stuck drill string, its individual elements, downhole motors or foreign objects from a well. By appointment L. and. conditionally divided into the main one (catchers, overshots, taps, bells, magnetic milling cutters, etc.), used for direct connection with the emergency object and its subsequent removal from the well, and auxiliary, which serves to study the emergency object and prepare for the elimination of the accident.
Catchers (Fig. 1) are used to extract the part of the drill string remaining in the well by connecting it to the top. end by gripping the outside of the pipe or lock.
The catcher consists of a body, in which axially movable dies are installed, fixed with dowels from rotation relative to the body. B lower part, the catcher is connected on the thread with a guide funnel, in the upper part - with an adapter or a pipe. Ha dies on their vnutr. The surface is left-handed. The contact surfaces of the body and dies are made conical, which ensures a secure grip on the top. end of the emergency pipe.
Extraction of an emergency drill string (length up to 400 m) by capturing its top. the end under is made by overshot. The overshot consists of a body, inside of which spring plates are installed, capturing the lock of the drill pipe. Having completely skipped the lock, the plates are installed with their top. ends against the support end of the lock, which ensures the capture of the pipe when lifting the overshot.
If top. the end of the emergency column ends int. thread, then taps are used for fishing. Taps with a right-hand thread are used to extract the remaining column as a whole, with a left-hand thread - for unscrewing and extracting the column in parts. Often, taps are used with a centering device (Fig. 2), which increases the accuracy of its entry into the hole of the emergency string. A signal indicating that the tap has entered the hole correctly is a pressure surge on the pump that supplies the flushing fluid.
Rice. 2. Tap with centering device: 1 - tap; 2 - funnel.
In cases where large torques and axial forces are required to eliminate an accident, bells (Fig. 3) are used, which are connected to the emergency pipe along its outer surface, or pipe spears (Fig. 4), which are used at large depths and small annular gaps between the wall wells and emergency pipe.
The fishing sleeve of the pipe spear is made longitudinally cut with conic. inner surface (inclination angle approx. 2°). The surface of the spear body contacting with it has the same angle. With the help of a guide cone, made at the end of the body, the spear is inserted into the emergency pipe. When lowering, the fishing sleeve first abuts against the end of the pipe and moves to the top. a position where, under the action of a part of the mass of the working string and due to the presence of a cut, it is compressed and goes inside the pipe. In the future, when the working string is tensioned, the fishing sleeve expands due to interaction with the body along the conic. surfaces and cuts into the body of the emergency pipe, providing a secure grip. The design of the spear eliminates the deformation of the pipe when it is captured.
To clean the bottom of the well from foreign metal. objects, a magnetic milling cutter is used (Fig. 5), consisting of an adapter, body, top. and lower poles, sleeve, magnet and crown. 
To clean the bottom of the well from foreign metal. objects by grinding them use downhole milling cutters. As an auxiliary L. and. a shoe mill is used, with the help of which the ends of the emergency columns are prepared and the destruction of the g. p. and metal. objects in the annular space between the emergency pipe and the wall of the well. To extract foreign objects from the face, so-called. spiders (Fig. 6).
Left in the well rope or logging cable is removed using the so-called. ruff (Fig. 7).
A funnel is placed above the ruff hooks, which serves to fix the retrieved rope and prevent it from jamming in the well. If the lifting capacity of the derrick and traveling system is insufficient to free the drill or casing string from sticking, then hydraulics are sometimes used for this purpose. jacks.
In cases where it is not possible to release a stuck string or it has complex fracture contours, L. and. are used, with the help of which the string is cut for the purpose of subsequent extraction from the well in parts. The pipe is cut from the outside with an external pipe cutter (Fig. 8).
To cut the pipe from the inside, use the inside. pipe cutters. The dismemberment of the emergency string is also carried out with the help of torpedoes, to determine the location of which in the well, a magnetic locator is used (Fig. 9). 
Rice. 9. Magnetic locator: 1 - case; 2 - coil; 3 - iron core; 4 - permanent magnets; 5 - bridge for candles; 6 - plug; 7 - tip; A - locator fragment.
With the help of the locator, the location of the coupling and interlock connections is recorded. B. C. Budyansky.
Mountain Encyclopedia. - M.: Soviet Encyclopedia. Edited by E. A. Kozlovsky. 1984-1991 .
- Lishtvan I. I.
See what "Fishing Tool" is in other dictionaries:
Tool - get a working discount coupon at Akademika Stroylandia or profitably buy a tool with free shipping on sale in Stroylandia
fishing tool- A tool for extracting relatively large objects from a well. It is lowered into the well on a steel rope Topics oil and gas industry EN bitchfishing ... ...
fishing tool for lifting pipes remaining in the well- fishing tap pipe tap — Topics oil and gas industry Synonyms fishing tappipe tap EN die nipple … Directory technical translator
fishing tool (in a borehole)- — Topics oil and gas industry EN finger grip … Technical Translator's Handbook- — Topics oil and gas industry EN collar socket … Technical Translator's Handbook
fishing tool for gripping the remaining tool by the neck- (with stripped thread) Subjects oil and gas industry EN collar grab … Technical Translator's Handbook
fishing tool for extracting a broken drill from a well- — Topics oil and gas industry EN coil drag … Technical Translator's Handbook
fishing tool for small items- — Topics oil and gas industry EN red and yellow basket … Technical Translator's Handbook
Fishing tools used to eliminate accidents in oil wells are diverse in types and designs.
For catching pipes are used:
- pipes,
- overshots,
- bells
- taps;
for fishing rods:
- slips,
- overshots,
- hooks;
for catching other items:
- fishing rods
- hooks
- ruffs,
- slings,
– magnetic milling cutters, etc.
Spears (internal and external, non-releasing and releasing) are available in several sizes depending on the diameter of the pipes to be retrieved. Spears are made in two versions: resting against the end of the gripped string and leading into the gripped string with left-hand threads. They can extract columns as a whole or in parts. At the request of the consumer, pipe spears can also be manufactured with right-hand threads.
The pipe is lowered into the well for drilling pipes and tubing and stop 3-5 m above the end of the remaining pipes in the well. Then the circulation of the flushing liquid is created and the tool is continued to be lowered while slowly rotating it to the right or left. When the spear is introduced into the extracted pipe, the rotation of the tool and the pumping of liquid are stopped and the pipe string is slowly pulled, walking it around if necessary. If the pipes are not amenable to pacing, the releasing spear can be released and lifted.
To catch broken tubing, the upper part of which is a bare end with a torn coupling, bells are used. The bell is a steel forged pipe of a special shape, having a thread for a coupling at the upper end. drilling lock or tubing, on which it descends into the well. On the inner surface in the lower part of the bell there is a conical bore, on which a fishing thread is cut and four or five longitudinal grooves are made for the chips to escape when the bell is cut into the pipe body.
An overshot is used to catch pipes by the sleeve. Inside the overshot are several flat springs. When the tool is lowered, the retrievable pipe, entering the overshot, pushes the springs apart and goes further, and the springs grab the pipe under the sleeve only in cases where the pipes are not stuck, since at high tensions the springs can break and remain in the well.
Taps belong to a group of tools introduced into the extracted objects. The body of the tap is made in the form of a truncated cone, the upper end of which has an internal locking thread for connection with the column drilling or tubing, and the lower one - a fishing thread with longitudinal grooves for the exit of chips when cutting into an emergency object.
For catching sucker rods, slip couplings and combined catchers are used. Catching perforators, cable and steel rope is carried out with various kinds of hooks, fishing rods and ruffs in the form of two- or three-horned forks, which capture the caught objects by the protruding parts. Small items (chains, keys, crackers, etc.) are removed by various spiders. For catching small metal objects, a magnetic milling cutter is used, consisting of a sub, a magnetic system and a body with a milling crown reinforced with crushed hard alloy.
Wells that cannot be drilled repair work by current repair teams and the implementation of which requires special equipment and tools are transferred for overhaul. Usually, a workover is carried out by a specialized department organized in an association, to which all work on wells associated with an increase in oil recovery layers. That's why it's called the Office of Promotion. oil recovery formations and workover of wells (UPNP and KRS). It contains all technical means, equipment, materials, vehicles, qualified engineering and technical service and teams.
In some cases, when in a given field certain types works are massive, such as, for example, acid treatments, they are transferred to a specialized workshop that performs only these works.
Such specialization improves the quality of work, their efficiency and helps to reduce occupational injuries.
A special place in the work on the overhaul of wells is occupied by fishing operations, the need for which arises in the event of a break or lapel of an underground equipment, tubing, rods, cable and other complications. When breaking and hitting the bottom, the detached part equipment is crushed, wedged in the casing and often puts the well out of action. To eliminate such accidents, after a reliable killing of the well, the so-called seal is first lowered into it to inspect the place of the break. Traces of the torn off part are imprinted on a lead or aluminum disk of a seal that is lowered into the well and pressed against the place of the break. , outlet hooks, fishing bells).
The capture of the broken end by the fishing tool, even if it succeeds, does not always end with the complete extraction of the broken part. equipment and well cleaning. Sometimes it is necessary to resort to the help of hydraulic jacks (when the tension of the traveling system exceeds the carrying capacity of lifting structures) and use them to extract the torn equipment. If such an attempt to clean the well again ends with a repeated breakage of the lowered tool ( drilling pipes), then to restore the health of the well, a second wellbore is drilled and operated as a new well. This work is carried out by a team overhaul using a special cutter and light drilling equipment. No less difficult is the work on the isolation of casing strings, in which defects were found as a result of corrosion or collapse, on the lapel and extraction of pipes stuck with cement; when you have to drill these pipes with special core bits or pipe cutters.
With intensive watering of the well, the problem arises of isolating the interlayer or the place through which water breakthrough into the well occurred. Such a breakthrough can occur along the annulus as a result of a violation of the integrity of the cement stone. In this case, water from aquifers enters the bottomhole and prevents the inflow oil from the productive layer. The source of watering can be a well-permeable interlayer occurring within the exposed thickness of the reservoir, through which water from the injection well penetrates to the bottom of the production well and reduces its productivity. Watering can also occur along the lower part of the productive horizon with the formation of a water cone in the bottomhole zone. In all cases, a thorough survey of the well is required using geophysical methods to detect sources of watering. Only after the analysis of the research data can specific measures for the technique and technology of water inflow isolation be developed and implemented. Works on isolation of water inflow do not always give the desired effect, however, the transfer of these works to the jurisdiction of a specialized organization significantly increases their success. There are many techniques for isolating water inflows, which boil down to pumping various plugging mixtures and materials, including special resins, into the flooded layer or into the annulus.
The specific performance of well workover work is regulated by the project and various instructional cards, which indicate the sequence of operations, the technical means used and equipment. The efficiency of the work performed is determined by comparing the results of the well survey before and after the overhaul, comparing its water cut, productivity factor and other indicators. With the aging of the well stock, an increase in the water cut of their production and an increase in the share of mechanized prey the need for repairs increases and the implementation of these works by traditional methods becomes a difficult task. In this regard, new technological methods have been developed that reduce labor and material and technical means for well repair.
The complex equipment includes: a tower with a working platform and walkways; traveling system; lifting winch or installation (unit); pumping unit; rotor; swivel; blowout preventer equipment; wellhead and underground tools.
