The basis of all Expro landing string assemblies originates with the systems developed for the exploration and appraisal (E&A) applications more than 25 years ago.  Providing equipment for standard 3”, large bore up to 5”, high pressure, deep water drill stem testing and even ESP exploration and appraisal activity, these systems can cover any of our clients’ needs.

Drill stem test strings are in-riser systems used to allow well operations to be conducted safely during Drill Stem Testing from a semi-submersible rig or drillship in water depths up to 10,000 ft. They provide the ability to rapidly shut-in the well and disconnect should conditions require it.

The Subsea Test Tree provides the primary dual afety barrier to contain well pressure cia two ball valves. In addition it provides a safe disconnect facility from the well in case of emergency. These valves can be configured to cut Coil Tubing and Wireline while maintaining sealing integrity. The ball closure logic allows a single ball to cut the coil tubing and wireline leaving full redundancy for the other ball to seal. The Tree ball valves support pressure applied from above allowing the string and latch seals to be pressure tested. The latch mechanism allows the string to be unlatched and re-latched as conditions require. The short overall length of the Test Tree enable two sets of BOP Rams to be closed below the Test Tree and the Shear Rams to be closed above the Tree.

A secondary disconnect system allows well isolation even in the event of total umbilical loss.

The Lubricator Valve is located below the rig floor providing an increased lubricator section to allow the safe deployment of either wireline or coil tubing equipment. This ball valve features bi-directional sealing to allow pressure testing from above and well pressure control from below. Inherent within the valve is a unique pump through feature enabling well kill operations to be performed.

The Retainer Valve is located just above the BOP Shear Rams and is designed, in the event of a disconnect, to isolate the landing string contents and vent trapped pressure from between the Retainer Valve and the Subsea Test Tree to the Marine Riser. It is operated by the latch control line and controlled by a series of mechanical and hydraulic interlocks. As the Landing String is bled, the Retainer Valve allows riser fluid to enter, displacing hydrocarbons from within the string. Fail-as-is or Fail-close options are available depending on the operating philosophy.

Electrical Submersible Pump Test String

Expro’s unique subsea electrical submersible pump test strings are in-riser safety systems designed to perform drill stem tests or extended well tests on subsea wells with an ESP installed. The ESP Test String contains a power connector allowing direct connection to the ESP without having to workover the ESP after a subsea disconnection.

The landing string consists of the standard Expro landing string components with a specially designed ESP Test Tree. The ESP test tree provides the primary safety barrier and disconnect facility but has in addition an ESP power cable contained within a secondary bore of the tree. This enables a high voltage wet connect system to be installed in the test tree’s latch mechanism which allows the electrical power cable to be disconnected and re-connected subsea without having to retrieve the ESP to surface.