Tubing-Conveyed Sampler Carrier

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The tubing-conveyed sampler carrier conveys multiple single-phase, pressure/volume/temperature (PVT) samplers on the drillstem test (DST) string as an alternative to using wireline—thereby eliminating the need for well intervention and multiple runs. The flush-joint, tubing-conveyed sampler carrier is positioned in the test string bottomhole assembly (BHA) above the packer and close to the producing zone. The carrier can accommodate up to four internally mounted samplers, two paired in the upper housing and two paired in the lower housing. A two-sampler short version of the carrier is available by removing the lower housing.

A pressure-activated trigger fires the samplers. A preselected high-accuracy rupture disk protects an atmospheric area behind the trigger from annulus pressure. One disk is required to fire each pair of samplers.

To fire the samplers at the required time, pressure is applied to the annulus to burst the disk and initiate the firing process. The upper- and lower-sampler pairs can use the same rupture disk value so that all four samplers can be fired at one time. However by using different disk values (available in 500 psi/3.4 MPa increments), sampling can be spaced out as required. A Weatherford WMG pressure/temperature memory gauge can be incorporated adjacent to the sampler intakes. All sampler intakes are close to the same depth because the lower samplers are inverted.

Applications

  • Offshore and onshore
  • Drillstem tests
  • Production tests

Features, Advantages and Benefits

  • The tubing-conveyed sampler carrier uses standard Proserv single-phase bottomhole samplers that are mounted internally for maximum protection.
  • Crossovers are available to match the connections of the bottomhole assembly (BHA) for added flexibility.
  • The PVT samplers and high-accuracy rupture disks are installed on the ground, which saves rig time.
  • Sampling flow periods can be optimized, which saves rig time.
  • The PVT samplers are incorporated into the drillstem test (DST) string to eliminate multiple wireline runs, which enhances the safety of personnel and reduces costs.
  • A short, two-sampler version of the carrier adds flexibility.
  • Elimination of premature firing of clock-initiated triggers (resulting from unforeseen delays) adds flexibility to the well test and sampling program.