Extended reach drilling is a directional drilling of very long horizontal wells. This extended reach wells could be described by their ratio of the measured depth (MD) vs. the true vertical depth (TVD) which shall be at least equal to 2.
The extremely long reach wells are typically drilled to distant reservoirs to reduce the infrastructure and operational footprint that would otherwise be required to access the resource.
Running long production casing and liner strings in extended reach wells are challenging and critical operations. When installing the liner, especially in the long horizontal section, problems may occur in reaching the desired depth due to limited compression ratings and also high friction between liner and hole. The liner assembly is often rotated to reduce the sliding friction. Once the liner is landed, it is usually cemented and needs to be rotated again to obtain homogeneous cementation and good bond quality. To rotate the liner, the connection requires high torque capabilities to sustain the occurring loads.
Integral connections could be used in order to use large diameter tubing. Reduced clearances between the successive well lining improves the sliding properties of the mud in the annulus which decreases the friction further.
During all these operations, tubular string shall keep its sealability performances in order to guarantee the well integrity.
In order to answer to this application, different connections have been developed:
Internal development allows Vallourec providing products with extreme performances which could be used for this type of very challenging application without compromising customer well's integrity.