Wireline tools Wireline (cabling)

1 wireline tools

1.1 natural gamma ray tools
1.2 nuclear tools
1.3 resistivity tools
1.4 sonic , ultrasonic tools
1.5 magnetic resonance tools
1.6 borehole seismic tools
1.7 cased hole electric line tools

1.7.1 cement bond tools
1.7.2 casing collar locators
1.7.3 gamma perforating tools
1.7.4 wireline pressure setting assemblies (wlspa)

wireline tools

wireline tools specially designed instruments lowered bore on end of wireline cable. individually designed provide number of particular services, such evaluation of rock properties, location of casing collars, formation pressures, information regarding pore size or fluid identification , sample recovery. modern wireline tools can extremely complicated, , engineered withstand harsh conditions such found in many modern oil, gas, , geothermal wells. pressures in gas wells can exceed 30,000 psi, while temperatures can exceed 500 deg fahrenheit in geothermal wells. corrosive or carcinogenic gases such hydrogen sulfide can occur downhole.

to reduce amount of time running in well, several wireline tools joined , run simultaneously in tool string can hundreds of feet long , weigh more 5000 lbs.

natural gamma ray tools

natural gamma ray tools designed measure gamma radiation in earth caused disintegration of naturally occurring potassium, uranium, , thorium. unlike nuclear tools, these natural gamma ray tools emit no radiation. tools have radiation sensor, scintillation crystal emits light pulse proportional strength of gamma ray striking it. light pulse converted current pulse means of photomultiplier tube (pmt). photomultiplier tube, current pulse goes tool s electronics further processing , surface system recording. strength of received gamma rays dependent on source emitting gamma rays, density of formation, , distance between source , tool detector. log recorded tool used identify lithology, estimate shale content, , depth correlation of future logs.wire line covered wire

nuclear tools

putting radioactive charge in wireline string



locked case radioactive source logging job

nuclear tools measure formation properties through interaction of reservoir molecules radiation emitted logging tool. 2 common properties measured nuclear tools formation porosity , rock density:

formation porosity determined installing radiation source capable of emitting fast neutrons downhole environment. pore spaces in rock filled fluid containing hydrogen atoms, slow neutrons down epithermal or thermal state. atomic interaction creates gamma rays measured in tool through dedicated detectors, , interpreted through calibration porosity. higher number of gamma rays collected @ tool sensor indicate larger number of interactions hydrogen atoms, , larger porosity.

most open hole nuclear tools utilize double-encapsulated chemical sources.

density tools use gamma ray radiation determine lithology , density of rock in downhole environment. modern density tools utilize cs-137 radioactive source generate gamma rays interact rock strata. since higher density materials absorb gamma rays better lower density materials, gamma ray detector in wire line tool able accurately determine formation density measuring number , associated energy level of returning gamma rays have interacted rock matrix. density tools incorporate extendable caliper arm, used both press radioactive source , detectors against side of bore , measure exact width of bore in order remove effect of varying bore diameter on readings.

some modern nuclear tools use electronically powered source controlled surface generate neutrons. emitting neutrons of varying energies, logging engineer able determine formation lithology in fractional percentages.

resistivity tools

in matrix has porosity, pore spaces filled fluid of oil, gas (either hydrocarbon or otherwise) or formation water (sometimes referred connate water). fluid saturate rock , change electrical properties. wireline resistivity tool direct injects current(lateralog-type tools conductive water based muds) or induces (induction-type tools resistive or oil based muds) electric current surrounding rock , determines resistivity via ohm s law. resistivity of formation used identify pay zones containing highly resistive hydrocarbons opposed containing water, more conductive. useful determining location of oil-water contact in reservoir. wireline tools able measure resistivity @ several depths of investigation bore hole wall, allowing log analysts accurately predict level of fluid invasion drilling mud, , determine qualitative measurement of permeability.

some resistivity tools have many electrodes mounted on several articulated pads, allowing multiple micro-resistivity measurements. these micro-resistivities have shallow depth of investigation, typically in range of 0.1 0.8 inches, making them suitable borehole imaging. resistivity imagers available operate using induction methods resistive mud systems (oil base), , direct current methods conductive mud systems (water based).

sonic , ultrasonic tools

sonic tools, such baker hughes xmac-f1, consist of multiple piezoelectric transducers , receivers mounted on tool body @ fixed distances. transmitters generate pattern of sound waves @ varying operating frequencies down hole formation. signal path leaves transmitter, passes through mud column, travels along borehole wall , collected @ multiple receivers spaced out along tool body. time takes sound wave travel through rock dependent on number of properties of existing rock, including formation porosity, lithology, permeability , rock strength. different types of pressure waves can generated in specific axis, allowing geoscientists determine anisotropic stress regimes. important in determining hole stability , aids drilling engineers in planning future design.

sonic tools used extensively evaluate cement bond between casing , formation in completed well, calculating accentuation of signal after passed through casing wall (see cement bond tools below).

ultrasonic tools use rotating acoustic transducer map 360 degree image of borehole logging tool pulled surface. useful determining small scale bedding , formation dip, identifying drilling artifacts such spiraling or induced fractures.

magnetic resonance tools

a measurement of nuclear magnetic resonance (nmr) properties of hydrogen in formation. there 2 phases measurement: polarization , acquisition. first, hydrogen atoms aligned in direction of static magnetic field (b0). polarization takes characteristic time t1. second, hydrogen atoms tipped short burst oscillating magnetic field designed precess in resonance in plane perpendicular b0. frequency of oscillation larmor frequency. precession of hydrogen atoms induces signal in antenna. decay of signal time caused transverse relaxation , measured cpmg pulse sequence. decay sum of different decay times, called t2. t2 distribution basic output of nmr measurement.

the nmr measurement made both laboratory instrument , logging tool follow same principles closely. important feature of nmr measurement time needed acquire it. in laboratory, time presents no difficulty. in log, there trade-off between time needed polarization , acquisition, logging speed , frequency of sampling. longer polarization , acquisition, more complete measurement. however, longer times require either lower logging speed or less frequent sampling.

borehole seismic tools
cased hole electric line tools
cement bond tools

a cement bond tool, or cbt, acoustic tool used measure quality of cement behind casing. using cbt, bond between casing , cement bond between cement , formation can determined. using cbt data, company can troubleshoot problems cement sheath if necessary. tool must centralized in function properly.

two of largest problems found in cement cbt s channelling , micro-annulus. micro annulus formation of microscopic cracks in cement sheath. channelling large, contiguous voids in cement sheath form, typically caused poor centralization of casing. both of these situations can, if necessary, fixed remedial electric line work.

a cbt gains measurements rapidly pulsing out compressional waves across bore , pipe, cement, , formation. compressional pulse originates in transmitter @ top of tool, which, when powered on surface sounds rapid clicking sound. tool typically has 2 receivers, 1 3 feet away receiver, , @ 5 feet transmitter. these receivers record arrival time of compressional waves. information these receivers logged traveltimes 3 , 5 foot receivers , micro-seismogram.

recent advances in logging technologies have allowed receivers measure 360 degrees of cement integrity , can represented on log radial cement map , 6-8 individual sector arrival times.

casing collar locators

casing collar locator tools, or ccl s, among simplest , essential in cased hole electric line. ccl s typically used depth correlation , can indicator of line overspeed when logging in heavy fluids.

ccl log

a ccl operates on faraday s law of induction. 2 magnets separated coil of copper wire. ccl passes casing joint, or collar, difference in metal thickness across 2 magnets induces current spike in coil. current spike sent uphole , logged s called collar kick on cased hole log.

gamma perforating tools

a cased hole gamma perforator used perform mechanical services, such shooting perforations, setting downhole tubing/casing elements, dumping remedial cement, tracer surveys, etc. typically, gamma perforator have sort of explosively initiated device attached it, such perforating gun, setting tool, or dump bailor. in instances, gamma perforator used merely spot objects in well, in tubing conveyed perforating operations , tracer surveys.

gamma perforators operate in same way open hole natural gamma ray tool. gamma rays given off naturally occurring radioactive elements bombard scintillation detector mounted on tool. tool processes gamma ray counts , sends data uphole processed computerized acquisition system, , plotted on log versus depth. information used ensure depth shown on log correct. after that, power can applied through tool set off explosive charges things perforating, setting plugs or packers, dumping cement, etc.

wireline pressure setting assemblies (wlspa)

setting tools used set downhole completion elements such production packers or bridge plugs. setting tools typically use expanding gas energy slow burning explosive charge drive hydraulic piston assembly. assembly attached plug or packer means of setting mandrel , sliding sleeve, when stroked piston assembly, squeezes elastomer elements of packing element, deforming sufficiently wedge place in tubing or casing string. completion packers or plugs have specially designed shear mechanism release setting tool element allowing retrieved surface. packer/plug however, remains down hole barrier isolate production zones or permanently plug off bore.