What happens with the wrong pipe size?
United States shale has created a boom in the domestic oil and gas industry and caused many companies to switch to onshore developments from offshore. While deep water developments provide a plethora of challenges, onshore has its own set of challenges, with smaller budgets, rapid development, and large numbers of interconnected wells. With pipe networks of interconnecting flows, determining the appropriate scenario to size a pipe can be challenging. Additionally, due to time constraints, many times rules of thumb are used to determine pipe size (or even worse the currently available pipe is used), which can frequently lead to under sizing and over sizing pipes.
The problems with undersized pipes are obvious, higher pressure drops and erosional velocities, however oversizing a pipeline can sometimes be just as bad (in addition to costing more). In multiphase flow, oversized pipes can lead to accumulation of liquids at low spots and gas pockets at high spots. These phase breakouts can choke flow and lead to higher pressure drops throughout the system. Additionally, stagnant fluids (especially water) in a pipeline can lead to increased risk of corrosion, which can lead to early pipe failure.
How do we size pipelines better?
To handle these challenges Assured Flow Solutions (AFS) has developed an automated adaptive line sizing algorithm, which can rapidly size pipelines for a large interconnected field (accelerating the process from weeks to hours). AFS’s line sizing tool can examine thousands of production dates/scenarios for a life of field development and determine the controlling cases. Once the controlling cases are understood, the line sizing tool uses a multiphase flow model to adaptively size the pipelines based on input constraints (e.g., pressure drop, erosional velocity). This ensures that the pipelines are sized appropriately. Additionally, any potential problem areas can be flagged for further examination by the engineers.
(line sizing adaptive algorithm at work, different colors represent different sized pipes)
Looking ahead
Our line sizing algorithm has been successfully deployed at several companies on several developments. Based on experience in these projects, we have developed an automated line looping algorithm and discussions are currently underway about development of a tool which will automate the placement of pig launcher and receivers.