Tubing-conveyed perforating (TCP) completion techniques enable perforating very long intervals in one run—some TCP strings have exceeded 8,000 ft [2,440 m] in length—and in highly deviated and horizontal wells TCP is the only means of accessing to the perforating depth. TCP also facilitates running large guns and using high underbalance. When TCP is deployed in conjunction with drillstem test (DST) tools, well fluids can be easily controlled. Without having to kill the well, TCP strings can be retrieved (shoot and pull) or left as part of the permanent completion (integrated TCP).
TCP Applications
Your choice of tubing-conveyed perforating (TCP) string design will vary depending on your completion type: temporary, permanent, or workover. The strings listed below include only the most common components for different TCP applications. Your Schlumberger representative can advise you on the most efficient string configuration for your application.
1-Firing Systems
BCF Ball-Activated Firing Head
The small-diameter coiled tubing (CT) firing head is recommended for use in guns 49.9 mm (1.69 in) or smaller in diameter.
CBF Circulation Ball Drop-Activated Firing Head
The most commonly used CT firing head, the CBF is available with multiple adapters to accommodate various CT dimensions and gun sizes. The head is insensitive to water-hammer effects and vertical drops.
DFS Differential Pressure Firing System
The DFS activates the differential pressure firing head by using the pressure created between the annulus pressure above the packer and the cushion or sump pressure below the packer.
BHF Drop-Bar Hydrostatic Firing Head
The drop-bar hydrostatic firing (BHF) head has a firing pin that is driven by hydrostatic pressure and does not depend on the intensity of drop-bar impact. Its features minimize the possibility of accidental firing and prevent and release trapped pressure.
eFire Electronic Firing Head System
eFire electronic firing head systems for coiled tubing, TCP and wireline provide a more efficient and economical method for a wide range of downhole explosive operations.
EOFH Extreme Overbalanced Firing Head
The direct pressure-activated head is designed for no-delay firing and is used mainly in extreme overbalanced perforating operations.
HDF Hydraulic Delay Firing Head
The hydraulic delay firing head is an absolute-pressure-operated firing head.
ProFire Programmable Firing Head
The ProFire programmable firing head uses hydromechanical technology to precisely control gun firing time when multiple operations are performed under pressure.
Redundant Firing Systems
TCF Trigger Charge Firing Systems
The trigger charge firing systems are designed to offer maximum flexibility and control over the firing operation because the firing head is run separately from the gun string.
Absolute Pressure-Actuated Trigger Charge Firing System TCF-P | Drop Bar-Actuated Trigger Charge Firing System TCF-DB | Jar Down-Actuated Trigger Charge Firing System TCF-JD
USTP Universal Setting Tool with Propellant
The USTP is used to set downhole equipment such as packers, bridge plugs, and the MAXR automatic release anchor on drillpipe, coiled tubing, slickline, or wireline.
2- TCP and Completion Perforating Accessories
SXPV Automatic Production Valve
An explosive production valve synchronized to open as soon as the perforating guns fire.
Debris-Circulating Sub Accessory
The debris-circulating sub consists of a ceramic cone seated in a ported sub, usually positioned between the packer and the guns, typically 30 ft above the firing head.
DTRV Drop-Bar-Triggered Surge Valve
Pressure-operated valve used to isolate the rathole from the tubing.
eSleeve Isolation Valve
A production valve with multiple applications that is activated by tubing or annulus pressure.
SXVA Explosively Initiated Vertical Shock Absorber
Absorbs the shock of the guns as they are detonated to prevent damage to packers, gauges, adjacent gun strings, etc.
FIS Fluid and Debris Isolation Sub
The fluid/debris isolation sub is an enhancement of the standard cone-type debris-circulating sub for heavy mud environments or large amounts of debris.
FLUP Fill-Up Valve
The pressure-operated fill-up valve is open to the annulus, allowing the tubing to fill while going down.
Gun Swivel
A gun swivel allows the gun string to rotate with respect to the tubing string.
Last-Shot Detection System
Compatible with all firing heads.
POUV Pressure-Operated Underbalance Valve
Pressure actuation and operation.
Radioactive Marker Sub
Accurate gun depth positioning.
3- TCP Gun Release Systems
CTXR Closed Tubing Explosive-Actuated Release
Automatically drops tubing-conveyed perforating (TCP) guns at the instant of detonation to the well bottom after the guns are fired. When the guns are fired in a closed system in which the tubing pressure is less than the wellbore pressure, the CTXR gun release disconnects the TCP guns.
CTR Controlled Tension Release
Allows retrieval of the running assembly if guns become stuck. The CTR is a fullbore safety release device for TCP operations. Pulling on the string with a predetermined tension and holding this tension for a predetermined time actuates the CTR.
MAXR Auto Release Gun Anchor
Primarily used to anchor high-shot-density (HSD) gun strings in monobore wells. The MAXR can be run in the hole with either wireline or pipe and is set with standard setting equipment.
SXAR Automatic Gun Release
Automatically drops tubing-conveyed perforating guns to the well bottom after the guns are fired. A full-tubing opening exists after the gun string is dropped, and the tailpipe incorporates a muleshoe entry wireline guide. Firing heads and no-gos are dropped as one piece for easy fishing.
TCR Tubing-Conveyed Gun Release
Enables TCP guns to be dropped off the end of the running string, allowing access to the perforated zone for stimulation, production logging, squeezing, or additional perforating. After the guns have dropped, the release housing acts as a tubing reentry guide.
WXAR Automatic Gun Release with X-Tools Technology
Automatically drops perforating guns at the instant of detonation. The WXAR, which extends the length of the gun strings that can be conveyed into the well, can be run on for wireline, tubing, or coiled tubing. Use of the WXAR enables long intervals to be perforated at underbalanced pressure without killing the well