How TCP Works

Tubing Conveyed Perforating (TCP) Bottom Hole Assemblies (BHA) typically consist of a firing head, percussion initiator, perforating guns, inter-gun time delayed detonators, a setting tool initiator, and a plug. The initiator, also known as the CP Detonator, is used to reliably initiate down-hole BHA for perforating operations in the oil and gas industry.
Mechanical impact energy from a firing head is converted to detonating output by the initiator which is needed to fire the initial gun in the BHA. Mechanical transfer devices are used in between perforating guns to initiate primers or igniters for time delayed detonators to provide reliable time for pulling to the next perforation cluster. Explosive transfer devices can also be used to join redundant or duplicate energetic paths for redundant initiation trains. Precise delay times are achieved between 5 and 6 minutes down-hole and are dependent upon Bottom Hole Temperatures (BHT). For more efficient operations, over thirty (30) time delay detonators have been reliably functioned on a single run in-between perforating guns. For plug and perf operations, mechanical impact energy from a firing head, or transfer device, functions a rapid deflagrating material (RDM) initiator which is used to reliably ignite propellants in setting tools to assure consistent burn rates prior to plug separation.

Benefits of TCP

Operational Efficiency. TCP allows the well operator to perforate long, or widely spaced, intervals simultaneously on a single trip into the well rather than having to make multiple runs on wireline. The difference between TCP and wireline-perforating rig time depends on interval length and the number of wireline descents vs. the additional time to position the string and prepare the well for TCP operations. However, TCP exposes the gun to the well environment longer than wireline perforating, a concern in high-temperature operations. TCP allows the well operator to perform a flow test immediately after perforating. Impulse-type testing techniques can identify the extent of wellbore damage before large investments in stimulation or gravel packing are made. In addition to impulse testing, a variety of other testing and completion equipment can be combined with the TCP string to provide for comprehensive reservoir evaluation immediately after perforating.

Under balanced Perforating. An imbalance, established between the formation and wellbore pressures before the TCP guns are fired, creates an instantaneous and controlled surge of formation fluids into the well, which cleans the perforations and enhances the well's productivity and injectivity.

Safety.

Surface well-control equipment is installed and tested before perforating, guaranteeing complete safety throughout all phases of the TCP operation. Phases of the TCP operation. High-Performance Perforating Systems. Gun size is limited by the ID of the casing, permitting the use of the largest possible charges permitting the use of the largest possible charges (either deeply penetrating or big-entry-hole type) and high shot densities. Guns can reconfigured to provide the optimum shot density and pattern for the specific application.

TCP Completion Types

Temporary TCP Completions. In a temporary TCP completion, the guns are run into the well at the end of a work string. After the guns are fired, and time is allowed for cleanup and testing, the well is killed with a non damaging completion fluid and the TCP string is removed. Completion procedures-backwashing, acidizing, procedures-backwashing, acidizing, fracturing, or gravel packing then be implemented. Large Intervals or Multizone Wells. Large intervals or wells where several widely spaced zones are combined into a single production string are completed efficiently on a temporary working. After perforating, the well is killed with a non damaging perforating, the well is killed with a non damaging completion fluid and the gun string is removed. This system affords the benefits of TCP while providing an alternative to leaving the gun string in the well where it could interfere with future operations. Gravel-Packed Wells. High-shot-density TCP guns loaded with big-entry-hole charges shot under balanced are used to perforate a zone to be gravel packed. After the perforated zone to be gravel gravel-packed. After cleanup, the well is killed with a non damaging completion fluid and the guns are retrieved to permit the running of screens and installation of the gravel pack. Testing. A well-control valve can be used in conjunction with TCP to provide a quick look at the near-wellbore region by impulse testing. A longer-duration drill stem test (DST)provides for a more detailed analysis of the commercial potential of the reservoir through observation of the types of fluids recovered and the flow rates. The DST/TCP combination ensures optimum perforation cleanup and provides reservoir performance characteristics. The system involves TCP guns running below the retrievable packer and a set of DST tools. Immediately after firing, the well was tested by alternately flowing and shutting in to develop the desired reservoir information.

Permanent TCP Completions. In a Permanent TCP Completions. In a permanent completion, the guns are run of permanent TCP completion, the guns are run of the end of the final completion string. The wellhead and safety equipment are installed before firing. The guns remain in the well after the perforating operation and may be dropped into the rathole if desired.

As a professional manufacturer of perforating guns, our perforating guns can guarantee very good quality, and our technical engineers can also make reasonable project planning according to your needs to help you save costs and reduce risks. If you are interested in Vigor's TCP or WCP perforating guns, please do not hesitate to contact us to get the best quality completion tools and the best quality procurement services.

For more information, you can write to our mailbox info@vigorpetroleum.com & marketing@vigordrilling.com