Deep Water Subsea Pipeline Intervention

Caltex offers multiple methods for accessing deepwater subsea flowlines and pipelines. Deposits that block flowlines can arise from various sources and often in hard-to-reach areas. Our expertise lies in helping customers identify the least invasive access methods. We prioritize utilizing existing subsea infrastructure, including subsea trees, jumpers, PLETs, manifolds, or umbilical ends, to gain access.

Alternate access methods include hot tapping, which is used when other access options are unavailable or when specific targets must be accessed. We employ technology that lifts or pumps the pipeline contents from the subsea environment to the surface vessel, allowing us to inventory as much of the contents as possible.

This process allows us to lower the flowline pressure below hydrostatic levels, generating the force needed to mobilize the blockage or introduce chemicals designed to interact with solids, softening or fluidizing them for de-inventory.

For large hydrate formations, the goal is to de-inventory as much product as possible while reducing the pipeline’s internal pressure. The target pressure should be below 10 bar absolute, which will typically release significant gas as the hydrate dissociates. The gas is vented to the surface to maintain low internal pressure. Chemicals such as methanol or methyl ethyl glycol (MEG) are introduced to aid in the disintegration of the hydrate.