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The Lease Pumpers HandbookChapter 17

Well Servicing and Workover

Section D

WIRE LINE OPERATIONS

D-1. Five Uses for Wire Lines inServicing Wells.

There are many styles of wire lineavailable for use in the oilfields. The wireused is generally either solid wire or wirerope. There are five major purposes for wirelines around well servicing units.

Surface uses: Guying the pulling unit Line from drum to blocksDownhole uses: Sand lines Solid wire lines Electric linesD-2. Wire Rope.

Wire rope consists of strands of solid wirebraided in specific patterns around a core tocreate various shapes (Figure 1). Theseparts of a wire rope are shown in Figure 2.

Figure 1. Typical shapes of wire rope.(courtesy of Williamsport Wirerope Works,

Inc.)

Figure 2. Parts of a wire rope.(courtesy of Williamsport Wirerope Works,

Inc.)

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Wire lines are available in right- and left-hand lay or twist (Figure 3).

Figure 3. Several types of wire rope lay.(courtesy of Williamsport Wirerope Works,

Inc.)

The correct method of measuring lines isshown in Figure 4. This is important whenselecting wire rope accessories such asclamps, blocks, and sheaves.

Figure 4. Methods of measuring lines.(courtesy of Williamsport Wirerope Works,

Inc.)

As illustrated in Figure 5, wire ropes canbe damaged. Extreme care must be used toprevent damage to the lines. Guy, sand, andall other lines must be protected. The linesshould always be inspected prior to use.

Figure 5. Typical wire rope problems.(courtesy of Williamsport Wirerope Works,

Inc.)

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D-3. Functions of Guy Lines.

Wire rope used for guy lines is usuallyright-hand regular lay. This line is availablein many sizes but is smaller than the linesused on the drum. When purchasing guylines, and the pumper should buy line thatwill not break under load and should checkwith the manufacturer to select the correctline and core.

D-4. Functions of Line from Drum toBlocks.

The draw works line used to drill an oilwell is different from the lines used on awell servicing unit. The wire rope used forwell servicing is rotation-resistant so that theelevators will remain in the same positionwhile traveling up through the derrick,especially when using a single line. Thelines are designed to be used on the surface.When purchasing a new line, the pumperwill need 500-800 feet or more in order tolower tubing blocks from the crown to thefloor. A reserve amount needs to be storedbehind the drum divider so that 20 or morefeet can be periodically cut off according tothe ton-mile schedule. This will extend thelife of the line.

D-5. Sand Lines.

Sand lines are placed on the second drumof the pulling unit or on the drum closer tothe cab. Many downhole services areperformed by the well servicing crew usingthe sand line, so it must be long enough toreach the bottom of the hole. Some typicalwell servicing crew services are:

Swabbing fluids. This operationinvolves dropping a swab down the holeand lifting fluid out to a vessel to remove

it from the tubing to a holding tank.When completing a new well, fracing, orperforming other operations, swabbing isnecessary to clean up the well bore andmatrix area. A satisfactory lubricatorwith the proper valves and accessories isneeded. Bailing sand. As fluids are produced,sand may migrate from the formationand settle in the bottom of the hole. Asand bailer may be lowered to thebottom of the hole when the tubing ispulled on some wells and the sandbailed. Cutting paraffin and scale. The wellservicing crew may cut paraffin andscale with the sand line with specialtools (Figure 6).

Figure 6. One style of paraffin scraper.

Running impression blocks. Anotherfunction of the sand line is to run animpression block. When a fish or looseobject in the hole is lost, the pumpermust go fishing to try to retrieve it.When fishing, it is often desirable to runan impression tool in and set it down onthe lost item in order to know how tograb hold of the object. A standard orhard impression block is a flat-bottomedtool made of lead. It resembles a flat-bottomed drill bit from a distance. Running scrapers. Before running apacker into the hole, the well servicingcrew generally runs a scraper slightlylarger than the packer to remove anyscale or paraffin. This also checks forcollapsed casing.

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Pulling standing valves. If problemsare encountered while checking for orlocating tubing leaks, a standing valvecan be dropped into the hole and thetubing filled with water. As the tubing ispulled, the water level will drop to thelevel of the hole. When that point isreached, the leaking joint is replaced.The sand line can be run in the hole toretrieve the standing valve withouthaving to pull the remaining joints.

D-6. Solid Wire Lines.

The solid wire line is a single strand ofwire. It is run into wells to perform specialtests and functions. Several sizes of wire areavailable, according the depth of the welland job to be performed. These jobs aregenerally tests or valve placement using adownhole tool usually referred to as a bomb.

Temperature surveys are run primarily todetect casing (or tubing) leaks, although theyserve other needs as well. Temperaturesurveys are run each six months to one yearto test for leaks in flowing wells. The leakwill be detected by a temperature drop ordecrease due to the expansion of theescaping gas.

Pressure surveys are run on a yearlyschedule to determine pressure drop andremaining reservoir fluids. By taking thepressure drop and comparing it to theprevious years reading, the remaining fluidsin the reservoir and the remaining life of thewell can be projected. This is also animportant factor in regulating theeffectiveness of gas injection and reservoirpressure maintenance. For flowing wells thedate when artificial lift may becomedesirable is projected and funds to install itcan be scheduled.

Directional surveys can also beconducted with a wire line while drilling awell. A clock in the survey bomb is set for apre-determined time and the tool is loweredinto the hole. After the appropriate time haslapsed, the clock will trigger the directionimpression on a small bulls eye disk, rotatethe disk 180 degrees, make a secondimpression, and retrieve the tool.

Solid wire lines are used to run andretrieve special tools, such as gas lift valvesin wells with side pocket mandrels. Thewire line machine is used to change gas liftvalves, scrape paraffin and scale, andperform several other functions. There areseveral other uses for the small solid linesuch as running, perforating, and retrievingblind plugs.

D-7. Electric Lines.

Electric lines are used for many purposesin oil wells. When a well is being drilled,open hole survey logs are run to evaluateformations that are being drilled todetermine if hydrocarbons encountered haveenough volume to make a commercial well.After the casing has been run, cased holelogs can also be conducted. When thecasing is cemented, this is usually followedwith a cement bond log.

In production operations electric logs arerun for many purposes. All wells areperforated by use of electric lines. They arealso used for measuring depth, conductingtemperature and pressure surveys, measuringpressure drop during fracing operations,running tracer surveys, and many otherpurposes.