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US 20070227737A1

(12) Patent Application Publication (10) Pub. No.: US 2007/0227737 A1 (19) United States

DELALOYE et al. (43) Pub. Date: Oct. 4, 2007

(54) METHOD AND APPARATUS FOR Related US. Application Data DOWNHOLE ARTIFICIAL LIFT SYSTEM PROTECTION (63) Continuation of application No. 10/892,524, ?led on

Jul. 15, 2004, noW Pat. No. 7,195,070.

(75) Inventors: RICHARD J. DELALOYE, Publica?m‘ classi?ca?‘m

Sugarland, TX (US); Steven (51) Int CL

Kennedy, HOuStOn, Je?'l‘ey BOde’ The Woodlands’ TX (Us); (52) us. Cl. ........................................................ .. 166/3051

Je?rey Lembcke, Cypress, TX (US); Kevin W. Smith, Houston, TX (US); (57) ABSTRACT Benjamin R- Lllscomb HI, Houston, A ?uid conditioning system designed to be installed between TX (US); Jack Curr, The Woodlands, the Well perforation and the intake of a pump used to effect TX (US) arti?cial lift is used to ?lter and chemically treat production

?uids. The ?uid conditioning system is an apparatus that provides scale inhibitors and/or other chemical treatments

Correspondence Address; into the production stream. In some embodiments, the ?uid WONG CABELLO LUTSCH RUTHERFORD conditioning system may be a part of the production stream & BRU’CCULERI, ’ ’ ?lter Wherein the ?ltering material is comprised of a porous L L P medium that contams and supports the treatment chemical.

' ' ' In other embodiments, the chemical treatment may be 20333 SH 249 accomplished by the gradual dissolution of a solid phase SUITE 600 chemical. The treating chemical may be recharged or replen HOUSTON, TX 77070 (Us) ished by various doWnhole reservoirs or feeding means. In

yet other embodiments, the treating chemical may be replen ished from the surface by means of a capillary tube. In

(73) Assignee: WEATHERFORD/LAMB, INC ., certain other embodiments, the apparatus may be retrievable Houston, TX (US) from the surface thereby permitting recharge or replenish

ment of the chemical in the apparatus on an as-needed basis. (21) Appl. No.: 11/681,064 The ?ltration apparatus may incorporate a bypass valve that

alloWs ?uid to by-pass the ?lter as sand or other particulate (22) Filed: Mar. 1, 2007 matter ?lls up or blocks the ?lter.

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US 2007/0227737 A1

METHOD AND APPARATUS FOR DOWNHOLE ARTIFICIAL LIFT SYSTEM PROTECTION

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of US. patent application Ser. No. 10/892,524 ?led Jul. 15, 2004, Which is hereby incorporated by reference in its entirety.

BACKGROUND

[0002] [0003] This invention relates to oil and gas Well produc tion technology. More particularly, it relates to the in situ treatment of ?uids produced by an arti?cial lift oil Well to inhibit the formation of scale inside and outside of produc tion tubing, pumps, valves, and the like and to reduce the amount of solids that enter the pump.

[0004] 2. Description of the Related Art

1. Field of the Invention

[0005] A typical oil Well produces not only oil, but also gas and Water, often in signi?cant quantity. The ?uids often transport solids, such as sand, as Well as other potentially damaging ?uids and gases, from the reservoir into the production tubing and casing, and up the production tubing to the surface. Equipment on the surface may be used to separate these production components. The oil is recovered; the gas, depending on its composition, may be ?ltered, treated and piped to a collection facility or ?ared off; the Water may be re-injected into another formation or, in the case of offshore production platforms, treated to prevent environmental contamination and then discharged over board; and the solids are separated and disposed of.

[0006] The oil and Water produced by oil and gas Wells often contains signi?cant quantities of dissolved minerals. Frequently, the Water is saturated With these mineralsiie, the Water contains the maximum concentration of the dis solved minerals possible at a given temperature and pres sure. Changes in temperature and/ or pressure Which occur as the ?uid is pumped from the production Zone through the Well to the treatment equipment on the surface can cause the minerals to come out of solution (“precipitate”) and become deposited on the interior and exterior surfaces of the pro duction tubing, pumps, valves, chokes and other equipment. The deposit is knoWn as “scale” and it can signi?cantly reduce the diameter and hence the capacity of production tubing. In extreme cases, the pipe or tubing can become completely obstructed, shutting doWn production. Even in less severe cases, Where the ?uid is not saturated, scale can build up on the interior and exterior of any exposed surface.

[0007] Certain dissolved minerals in Water are knoWn as “hardness ions”idivalent cations that include calcium (Ca+ 2), magnesium (Mg+2) and ferrous (Fen) ions. Hardness ions develop from dissolved minerals, bicarbonate, carbon ate, sulfate and chloride. Heating Water containing bicar bonate salts can cause the precipitation of a calcium car bonate solid. Raising the pH can alloW the Mg+2 and Fe+2 ions to precipitate as Fe(OH)2 and Mg(OH)2. Excess sodium carbonate can precipitate Ca+2 as CaCO3.

[0008] Precipitation is the formation of an insoluble mate rial in a solution. Precipitation may occur by a chemical reaction of tWo or more ions in solution or by changing the

Oct. 4, 2007

temperature of a saturated solution. There are many examples of this important phenomenon in drilling ?uids. Precipitation occurs in the reaction betWeen calcium cations and carbonate anions to form insoluble calcium carbonate: Ca+2+CO3—2QCaCO3.

[0009] Scale is a mineral salt deposit or coating formed on the surface of metal, rock or other material. Scale may be caused by a precipitation resulting from a chemical reaction With the surface on Which it forms, precipitation caused by chemical reactions, a change in pressure or temperature, or a change in the composition of a solution. The term “scale” is also applied to a corrosion product. Typical scales are calcium carbonate, calcium sulfate, barium sulfate, stron tium sulfate, iron sul?de, iron oxides, iron carbonate, the various silicates and phosphates and oxides, or any of a number of compounds insoluble or slightly soluble in Water.

[0010] Scale may be deposited on Wellbore tubulars, doWn hole equipment, and related components as the saturation of produced Water is affected by changing temperature and pressure conditions in the production conduit. In severe conditions, scale creates a signi?cant restriction, or even a plug, in the production tubing. Scale build-up in the arti?cial lift pump can lead to failure of the pump due to blocked ?oW passages and broken shafts. Scale removal is a common Well-intervention operation. A Wide range of mechanical, chemical and scale inhibitor treatment options are available to effect scale removal.

[0011] Scale can also occur in tubing, the gravel pack, the perforations or the formation itself. Scale deposition occurs When the solution equilibrium of the Water is disturbed by pressure and temperature changes, dissolved gases or incompatibility betWeen mixing Waters. Scale deposits are the most common and most troublesome damage problems in the oil ?eld and can occur in both production and injection Wells.

[0012] All Waters used in Well operations can be potential sources of scale, including Water used in Water?ood opera tions and ?ltrate from completion, Workover or treating ?uids. Therefore, reduction of scale deposition is directly related to reducing the amount of bad Water that is produced.

[0013] Carbonate scale is usually granular and sometimes very porous. A carbonate scale can be easily identi?ed by dropping it in a solution of hydrochloric acid Where bubbles of carbon dioxide Will be observed e?‘ervescing from the surface of the scale. Sulphate scales are harder and more dense. A sulphate deposit is brittle and does not e?‘ervesce When dropped in acid. Silica scales resemble porcelaini they are very brittle, not soluble in acid, but dissolve sloWly in alkali.

[0014] Scale removal is a common Well-intervention operation involving a Wide variety of mechanical scale inhibitor treatments and chemical options. Mechanical removal may be done by means of a pig or by abrasive jetting that cuts scale but leaves the tubing intact. Scale inhibition treatments involve squeeZing a chemical inhibitor into a Water-producing Zone for subsequent commingling With produced ?uids, preventing further scale precipitation. Chemical removal is performed With different solvents according to the type of scale:

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[0015] Carbonate scales such as calcium carbonate or calcite [CaCO3] can be readily dissolved With hydro chloric acid [HCl] at temperatures less than 250° F. [121° C.].

[0016] Sulfate scales such as gypsum [CaSO4.2H2O] or anhydrite [CaSO4] can be readily dissolved using eth ylenediamine tetraacetic acid (EDTA). The dissolution of barytine [BaSO4] or strontianite [SrSO4] is much more di?icult.

[0017] Chloride scales such as sodium chloride [NaCl] are easily dissolved With fresh Water or Weak acidic solutions, including HCl or acetic acid.

[0018] Iron scales such as iron sul?de [FeS] or iron oxide [Fe2O3] can be dissolved using HCl With seques tering or reducing agents to avoid precipitation of by-products, for example iron hydroxides and elemen tal sulfur.

[0019] Silica scales such as crystalliZed deposits of chalcedony or amorphous opal normally associated With steam?ood projects can be dissolved With hydrof luoric acid

[0020] Calcium scales such as calcium sulfate, calcium carbonate and calcium oxalate are insoluble in Water. HoW ever, all three are soluble in a Sodium Bisulfate acid solution. Calcium scale can be removed With an acid Wash using a 5-15% solution of Sodium Bisulfate (SBS). SBS can also be used during a shut doWn to remove scale by re-circulating it throughout areas of the process Where needed. The concentration of SBS solutions and the re circulation time depend on the amount of scale that needs to be removed. SBS can be a substitute for sulfamic acid in calcium scale removal situations.

[0021] Zinc sul?de (ZnS) is another one of the oil ?eld scales that plagues production. Although it does not seem to be common, according to ?eld experience and published literature, it causes a signi?cant ?oW/production problem When it does occur, just as all other scales adversely affect Wells. Other scales, such as barium sulfate and strontium sulfate, also cause production problems but are much harder than ZnS.

[0022] Although chemical solvents have been used on these harder scales, the results are often disappointing. While mechanical scale removal has been used successfully on barium and strontium sulfate scales With excellent suc cess, it had not been used on ZnS scale. It Was conceivable that the softer scale may not respond to the same process that removed harder scales.

[0023] In certain cases, scale may be an environmental or health haZard. The State of Louisiana, Department of Envi ronmental Quality has issued a noti?cation concerning a potential health haZard associated With handling pipe used in oil and gas production that may be contaminated With radioactive scale from naturally-occurring radioactive mate rials (NORM). The concern is the possible inhalation and/or ingestion of scale particles contaminated With radium-226 and possibly other radioactive material that may become airborne during Welding, cutting or reaming pipe that con tains radioactive scale. The State of Louisiana is using the term Technologically Enhanced Natural Radiation (TENR) for this material that is a subset of the NORM group.

Oct. 4, 2007

[0024] An inhibitor is a chemical agent added to a ?uid system to retard or prevent an undesirable reaction that occurs Within the ?uid or With the materials present in the surrounding environment. Arange of inhibitors is commonly used in the production and servicing of oil and gas Wells, such as corrosion inhibitors used in acidiZing treatments to prevent damage to Wellbore components and inhibitors used during production to control the effect of hydrogen sul?de [H28] [0025] A scale inhibitor is a chemical agent added to a ?uid system to retard or prevent an undesirable reaction that occurs Within the ?uid or With the materials present in the surrounding environment. Arange of inhibitors is commonly used in the production and servicing of oil and gas Wells, such as corrosion inhibitors used in acidiZing treatments to prevent damage to Wellbore components and inhibitors used during production to control the effect of hydrogen sul?de [H23] [0026] A sequestering agent (or chelation agent) is a chemical Whose molecular structure can envelop and hold a certain type of ion in a stable and soluble complex. Divalent cations, such as hardness ions, form stable and soluble complex structures With several types of sequestering chemicals. When held inside the complex, the ions have a limited ability to react With other ions, clays or polymers. Ethylenediamine tetraacetic acid (EDTA) is a Well-known sequestering agent for the hardness ions, such as Ca”, and is the reagent solution used in the hardness test protocol published by API. Polyphosphates can also sequester hard ness ions. Sequestering is not the same as precipitation because sequestering does not form a solid. For calcium carbonate deposits, glycolic and citric acids and ammonium salts and blends incorporating EDTA are used as chelants.

[0027] A scale-inhibitor squeeZe is a type of inhibition treatment used to control or prevent scale deposition. In a scale-inhibitor squeeZe, the inhibitor is pumped into a Water producing Zone. The inhibitor is attached to the formation matrix by chemical adsorption or by temperature-activated precipitation and returns With the produced ?uid at su?i ciently high concentrations to avoid scale precipitation. Some chemicals used in scale-inhibitor squeeZes are phos phonated carboxylic acids or various polymers.

[0028] Some scale-inhibitor systems integrate scale inhibitors and fracture treatments into one step, Which guarantees that the entire Well is treated With scale inhibitor. In this type of treatment, a high-e?iciency scale inhibitor is pumped into the matrix surrounding the fracture face during leakolf. It adsorbs to the matrix during pumping until the fracture begins to produce Water. As Water passes through the inhibitor-adsorbed Zone, it dissolves su?icient inhibitor to prevent scale deposition. The inhibitor is better placed than in a conventional scale-inhibitor squeeZe, Which reduces the re-treatment cost and improves production.

[0029] Some Well treatment systems continuously inject the treating chemical in the Well using a metering pump. The chemicals are either injected beloW the pump using a capillary line or injected into the Well annulus. When chemicals are injected into the Well annulus the chemicals build up in the Well bore until the pump pulls them doWn the Wellbore and into the pump intake.

[0030] Due to the time that it takes for the chemicals to reach the pump, changes in chemical mix or injection rates

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are very sloW to affect the ?uids entering the pump. If the pump intake is above the electric motor in an Electric Submersible Pump, ESP installation, the chemicals do not protect the motor or the casing beloW the pump intake.

[0031] In capillary injection systems, the location of the chemical injection can be determined When the system is installed by terminating the capillary tube beloW the pump intake/motor combination in an ESP completion. The cap illary injection tube provides continuous treatment of the ?uids and the time delay for adjustments to the blend of chemicals and/ or treatment rate can be minimiZed.

[0032] Sand produced With the ?uids can cause damage to pumping systems. Abrasion resistant pumps With engineered ceramic bearings and coated ?oW passages have been devel oped to improve pump life in Wells that produce sand, but sand Will eventually Wear out even these special sand tolerant pumps.

[0033] One practice for removing sand from the ?uid is by installing a liquid and sand separator betWeen the casing perforations and the pump intake. These systems deposit the separated sand into the Well’s rat hole or into tubing hung from the bottom of the separator as a trap. Wilson discloses a means for removal of sand separated With a doWnhole sand separator in US. Pat. No. 6,216,788.

[0034] Gravel packing is a sand-control method used to prevent the production of formation sand. It involves the placement of selected gravel across the production interval to prevent the production of formation ?nes or sand. Any gap or interruption in the pack coverage may permit unde sirable sand or ?nes to enter the producing system.

[0035] In gravel pack operations, a steel screen is placed in the Wellbore and the surrounding annulus is then packed With prepared gravel of a speci?c siZe that is designed to prevent the passage of formation sand. The primary objec tive is to stabiliZe the formation While causing minimal impairment to Well productivity.

[0036] Wire-Wrapped screen is one type of screen used in sand control applications to support the gravel pack. The pro?led Wire is Wrapped and Welded in place on a perforated liner. Wire-Wrapped screen is available in a range of siZes and speci?cations, including outside diameter, material type and the geometry and dimension of the screen slots. The space betWeen each Wire Wrap must be small enough to retain the gravel placed behind the screen, yet minimiZe any restriction of production.

[0037] A sand ?lter as described by Stanley in US. Pat. No. 4,977,958 is used to ?lter the sand out of the ?uid prior to entering the pump intake. This style of intake ?lter has been installed in numerous Wells and is effective for removal of solids, but once the ?lter is full of sand, ?uid ?oW through the ?lter is restricted and a large pressure drop occurs. As the pressure drop increases, the rate of sand accumulation increases causing the rate of pressure drop to increase until eventually the ?uid ?oW across the ?lter ceases. When ?uid ?oW to the pump ceases, the pump Will cavitate and even tually fail.

SUMMARY OF THE INVENTION

[0038] A ?uid conditioning system is installed betWeen the Well perforations and the intake of a pump used to effect

Oct. 4, 2007

arti?cial lift. The ?uid conditioning system is an apparatus that provides scale inhibitors and/or other chemical treat ments into the production stream. The production stream may also be ?ltered by the apparatus prior to the production stream’s introduction into the pump. In some embodiments, the ?uid conditioning system may be a part of the production stream ?lter Wherein the ?ltering material is comprised of a porous medium that contains and supports the treatment chemical. In other embodiments, the chemical treatment may be accomplished by the gradual dissolution of the unsupported solid phase chemical itself. The treating chemi cal may be recharged or replenished by various doWnhole reservoirs or feeding means. In yet other embodiments, the chemical treatment may be replenished from the surface by means of a capillary tube. In certain other embodiments, the apparatus may be retrievable from the surface by means of a Wireline or coil tubing thereby permitting recharge or replenishment of the chemical in the apparatus on an as needed or periodic basis. The ?ltration apparatus may incor porate a by-pass valve that alloWs ?uid to by-pass the ?lter as sand or other particulate matter ?lls up or blocks the ?lter.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0039] FIG. 1 is a cross-sectional vieW of an arti?cial lift pump equipped With an intake screen having a single-layer treatment space.

[0040] FIG. 2 is a typical ?oW curve for a by-pass valve.

[0041] FIG. 3 is a cross-sectional vieW of an arti?cial lift pump equipped With an intake screen having at least tWo annular treatment spaces.

[0042] FIG. 4 depicts the apparatus of FIG. 3 additionally equipped With a packer, shear sub and cross-over sub.

[0043] FIG. 5 is a cross-sectional vieW of the intake screen portion of the apparatus shoWn in FIG. 4 taken along line V-V.

[0044] FIG. 6 is a cross-sectional vieW of an arti?cial lift pump equipped With a multiple layer intake screen having capillary tube recharge means.

[0045] FIG. 7 is an alternative embodiment of the appa ratus shoWn in FIG. 6 Which includes means for distributed recharge of the treatment chemicals.

[0046] FIG. 8 is a cross-sectional vieW of an arti?cial lift pump equipped With a dual-layer intake screen equipped With a doWnhole replenishment means for solid-phase chemicals.

[0047] FIG. 9 is an alternative embodiment of the appa ratus shoWn in FIG. 8 Which has means doWnhole replen ishment of both solid-phase and liquid-phase chemicals.

[0048] FIG. 10 is a cross-sectional vieW of an arti?cial lift pump that has a dual-layer intake screen equipped With a doWnhole replenishment means for liquid-phase chemicals.

[0049] FIG. 11 is a cross-sectional vieW of an alternative embodiment of the apparatus shoWn in FIG. 10.

[0050] FIGS. 12A and 12B are cross-sectional vieWs of production tubing having capillary tubing incorporated Within their Wall structure.

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[0051] FIG. 13 is a cross-sectional vieW of an arti?cial lift pump equipped With a Wireline (or slickline) retrievable, chemical treatment intake screen.

[0052] FIG. 14 is an alternative embodiment of the appa ratus shown in FIG. 13 that further comprises an extension of the shroud around the pump and intake sections.

[0053] FIG. 15 is a cross-sectional vieW of a shaft-driven arti?cial lift pump equipped With a chemical treatment intake screen situated betWeen the pump and its driving motor.

[0054] FIG. 16 is a cross-sectional vieW of an alternative embodiment of the apparatus of FIG. 15 Wherein the screen is located Within the interior portion of the intake ?lter.

DETAILED DESCRIPTION OF THE INVENTION

[0055] Advances in electric motor technology have made Electric Submersible Pumps (ESPs) an increasingly popular method of providing arti?cial lift for oil Wells. Operating in the harsh conditions of the doWnhole environment, an ESP must be protected from ingesting corrosive, abrasive, or any other detrimental substance in the production ?uids in order to provide a Mean Time BetWeen Failure (MTBF) that justi?es its use on an economic basis. In addition, treating the production ?uids While doWnhole minimiZes the poten tial haZards involved in bringing the production ?uids to the surface While the production ?uids may contain any detri mental substance. Moreover, scale build-up in production tubing and pump chambers must also be controlled in order to decrease the number of Well interventions or Workovers needed during the useful life of an oil Well.

[0056] The present invention is a novel apparatus and method Which combines the functions of preventing ?nes or sand from entering the pump With the introduction of a scale inhibitor or other chemical treatments into the production stream prior to entering the pump. In an alternative embodi ment the production stream may be treated for environmen tal haZards after entering the pump.

[0057] Referring noW to FIG. 1, arti?cial lift system 10 includes pump 100 attached at its outlet end to production tubing 12 and at its inlet to inlet connector 14 Which is in ?uid communication With ?lter assembly 16. Filter assembly 16 is preferably designed such that Wellbore ?uid Will pass from the exterior 21 of external tubular 22 through external tubular 22 through any medium 30 through internal tubular 24 and into the central passage 28 of internal tubular 24. Arti?cial lift system 10 may be generally circular in cross section and siZed to ?t Within the production casing of a Well [not shoWn In some embodiments, pump 100 may be an ESP that receives electrical poWer from the surface via an electrical cable Within the Well bore [not shoWn].

[0058] Filter assembly 16 comprises top plate 18 and bottom plate 20. Top plate 18 alloWs internal tubular 24 to pass through its center portion and may be joined to inlet connector 14 in a ?uid tight manner. Top plate 18 and bottom plate 20 are connected by an external tubular 22 and by an internal tubular 24. The external tubular 22 may be a screen or other type of porous structure that alloWs a desired Wellbore ?uid to pass from one side of the tubular to the other While restraining the passage of undesired Wellbore ?uids or solids. The internal tubular 24 may be a screen or

Oct. 4, 2007

other type of porous structure that alloWs a desired Wellbore ?uid to pass from one side of the tubular to the other While restraining the passage of undesired Wellbore ?uids or solids. Together, external tubular 22 and internal tubular 24 de?ne annular space 32 Which may be used to contain medium 30[partially shoWn in FIG. 1 for clarity].

[0059] Should the ?lter assembly 16 become at least partially clogged With solid or other matter that may be present in the Wellbore such that Wellbore ?uid can no longer pass through the ?lter assembly 16 and reach the arti?cial lift system 10 then the arti?cial lift system 10 may be severely damaged. Such damage may result from such causes as pump cavitation. In cases Where the Wellbore ?uid is used to cool the arti?cial lift system’s motor, a partially clogged ?lter assembly may reduce the ?oW of cooling Wellbore ?uid to the extent that motor overheating may also occur. In order to prevent such damage to the arti?cial lift system, a by-pass valve 132 may be installed. Typically, although not alWays, the bottom plate 20 may have an opening through its center that alloWs ?uid to pass directly from the Well-bore into the central passage 28 of the internal tubular 24. Aby-pass valve 132 is located in the opening through the bottom plate 20. The by-pass valve 132 may be a ball valve, a spring-loaded valve, a poppet valve, a shear assembly, rupture disc, or any other type of valve that may be activated to relieve differ ential pressure. In some embodiments When the pressure drop across the screen equals the by-pass setting, the by-pass valve 132 partially opens and Wellbore ?uid is alloWed to by-pass the ?lter assembly 16. As ?uid by-passes the ?lter assembly 16, the ?oW rate through the ?lter is reduced; thus, the pressure drop is reduced for the matter-packed ?lter. With the by-pass valve 132 partially open, a portion of the Wellbore ?uid ?oWs into the central passage 28 through the ?lter assembly and a portion ?oWs into the central passage 28 through the by-pass valve 132. The proportions of Wellbore ?uid that pass through the ?lter assembly 16 and the by-pass valve 132 can be represented by Q (total ?oW)=Qf (?oW through ?lter assembly)+Qb (by-pass ?oW). As time passes, Qf Will be reduced as more Wellbore matter packs into the ?lter assembly 16 and the P (pressure) drop increases for a given ?oW rate thus causing Qb to increase. A typical ?oW curve is illustrated in FIG. 2. As the pressure drop across the ?lter assembly 16 increases, a larger fraction of the total ?oW passes through the bypass valve 132. Those skilled in the art Will appreciate that different bypass valve designs Will exhibit different ?oW curves. In an alternative embodiment, Where a by-pass valve 132 is provided, the by-pass valve 132 could open just prior to the point at Which Wellbore ?uid ?oW is reduced to the level that damage to the arti?cial lift system is predicted to occur. In addition, activation of the bypass valve should alert the operator on the surface that the ?lter assembly 16 might require service. Such service may be in the form of removal of the entire arti?cial lift system and ?lter assembly, reverse operation of the arti?cial lift system, or back-?ushing ?uid through the system from the surface so as to force out matter that may have accumulated in the ?lter assembly.

[0060] External tubular 22 may be any porous material With sufficient corrosion resistance and structural strength to Withstand the torque, Well obstructions, tension loading, compression loading, pressure differentials or any other conditions that may be encountered during insertion in the production casing and operation of the arti?cial lift system. In certain embodiments, external tubular 22 may be a Wire

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