Fighting Scales in Oil and Gas Production Systems – a Challenging Flow Assurance Case Study

Maturing oilfields has not just caused problems of large water handling but also demands novel flow assurance solutions which are practical and cost-effective. One of the major problems experienced in the oil production industry is the formation of mineral scale. Scales can form from the formation water as it undergoes changes in pressure and temperature, and tend to deposit on surfaces.  Its formation causes flow reduction or even blocking of pipes, valves and other process equipment.

The main implications of the problem are:

• Economic; due to downtime equipment replacement, reduced or lost production
• Safety; Equipment failures due to under-deposit corrosion can cost lives.

Summarized, the impact of scales in Oil & Gas surface equipment can be serious and challenges in removal, prediction and prevention are numerous.

An approach was developed for utilizing prediction-based knowledge on the scaling problem to formulate a workflow for flow assurance monitoring. The workflow is also intended to aid in arriving at practical and cost-effective mitigation strategy for problems related to scaling in surface equipment. The following are the brief steps involved in the workflow:

• Identify & define the key Issues (such as production shortfalls, pressure anomalies, etc.)
• Define objectives and specify boundaries
• Model process (multiphase network model)
• Analyze Results and employ a variety of techniques to pin down the causes
• Conduct a structured assessment to determine/evaluate solutions
• Develop an action plan / process redesign for implementing the solutions