I’ll start this series with a brief discussion on why does the oil & gas industry use subsea production and processing. We will be driving towards the effects of sand on this infrastructure after coving some background information.

Reduce cost of field development

• Do not need manned, surface-access, air-breathing facility
• Tie in step-out or marginal or nearby field
• Ideally, eliminate all water-based structures (fixed and floating) and bring hydrocarbons to shore for processing

Level 1: Production

• Wellhead and flow line
• Bring all fluid phases to central/onshore processing plant with natural flow

Level 2: Production w/ Energy Addition

• Wellhead, flow line, and multiphase pump
• Energy added to fluid phases to enable sufficient flow rate for economic development

Level 3: Production w/ Processing

• Wellhead, flow line, multiphase pump, and production separator
• Separation needed to remove bulk of free liquid phase
• Free up volume in pipeline and reduce amount of energy required to move liquid phase (e.g., no need to pump water to surface)

References:

1. Rawlins, C.H. and Ditria, J.C., 2019. “The Subsea Sand Management Challenge – What to do with the Sand?”. Offshore Technology Conference, Houston, TX, 6-9 May, OTC-29278-MS. https://doi.org/10.4043/29278-MS
2. Rawlins, C.H. 2019. “Enhanced Production Through Surface Facilities Sand Management.” SPE Distinguished Lecturer presentation. Link here
3. eprocess-training.com

Next week I will discuss some specific unit operations in subsea processing.