Engineering Analysis of Light Well Intervention Systems
Maximise operability, minimise loads and prevent overload with AS Mosley’s Riserless Light Well Intervention Services.
Riserless Light Well Intervention (RLWI) is performed using a Subsea Lubricator System that is usually deployed from a small monohull vessel. The Subsea Lubricator comprises a control package and a free-standing riser which is used to house the wireline tool string prior to deployment into the well. The Lubricator assembly is run and attached to the subsea Tree via the Tree Running Tool (TRT).
Riserless Light Well Intervention systems impose very low loads onto the Subsea Tree and wellhead during normal operations. Nevertheless, the attached lines (e.g. WL, guidelines and umbilicals) may snag during accidental vessel excursions – inducing relatively high loads. It is important to keep the wireline away from the control umbilical, especially during tool-running. Another important consideration is the length of the free-standing riser which must be intrinsically stable in all conditions. Limiting riser deflection is also critical to enable loading of the wireline tools with the ROV. Riser deflections can be amplified through second order mass effects especially at high wellhead angles in extreme currents.
AS Mosley has over 22 years of experience in modelling and performing design optimisation of Subsea Lubricator systems. We maximise operability and prevent overload even during accidental conditions. We also advise on suitable systems for minimising loads on very weak subsea equipment.
For more information on Riserless Light Well Intervention Services please get in touch.