Field optimization using IHS Piper – Part I: Optimising gathering systems

IHS Piper gives operators the tools to identify common operational issues and test potential corrective measures

In times of low commodity prices, it is valuable to have a tool that facilitates quick identification of surface gathering system bottlenecks and provides an interface to test optimization scenarios. IHS Piper is an application ideally suited for this purpose. A common approach to evaluating gathering system optimization includes:

1. Analyzing the existing gathering system for operational issues
2. Creating scenarios and testing their future effects on the gathering system
3. Generating economics to make quantifiable decisions for strategic gathering system management
   

Before using the IHS Piper application or any tool to evaluate the economics of a gathering system and testing ways to improve profitability or decrease operating costs, you need a calibrated field model. The process of model calibration in IHS Piper will not be reviewed in this article. However, references describing the calibration process, including videos and articles, are provided at the end of this article.

1. Analyzing the existing gathering system for operational issues

Often, many operational issues can be corrected for a relatively low cost and result in a significant improvement in field operations. If a valve were partially closed it would add a frictional pressure loss to the system. If that valve were opened fully, those frictional pressure losses would be substantially reduced for minimal investment. Common issues like partially closed valves, obstructions and clogged air filters are relatively simple operational issues that can be easily uncovered using IHS Piper. More complicated operational issues can be more difficult to uncover, including liquids dropping out or stagnating in low points in the gathering system. IHS Piper includes features to help you identify areas impacted by operational issues and aid in the determination of the cause. Once field issues are identified, a list of causes and remedies can be valuable when doing field reviews. For example a pipeline with very high frictional pressure losses may be remedied by twinning the line or sending partial rate to an alternate location to reduce friction in that pipeline.

2. Creating scenarios and testing their future effects on the gathering system

To determine if a potential change in operations or field configurations is worth pursuing, you will need to have a baseline model to compare scenarios. This baseline model is frequently called a "Base Case" scenario, and should be used to test the practicality of any alternate scenario(s). Using your calibrated IHS Piper Base Case Model, you can run a future forecast of your field. The forecasted production will represent how the field may perform in the future if you do not make any changes to the gathering system. This is your Base Case, and key performance indicators for alternate scenarios will be compared against it.

After you have considered what impact changes to the field might have based on your analysis of the system, you can compare model results between the Base Case and various alternate scenarios to determine the best option going forward. Piper has multiple built in diagnostic maps that help you quickly identify areas of concern.

3. Generating economics to make quantifiable decisions for strategic gathering system management

Once you have multiple scenarios built, you can use the economics feature to compare cash flow at individual facilities and the field as a whole. One powerful tool is the ability to compare the value of your field with different commodity price regimes.

Your findings may indicate that one of your alternate scenarios is ideal, or that additional scenarios need testing, or that the current gathering system is the best configuration for current market conditions. If you use diagnostic maps, production rates and economic indicators for your models, your decisions will be based upon quantifiable data that can be presented in an impactful visual format.

When testing the practicality and feasibility of an alternate scenario, you should always consider:

• The economic impact of changes, relative to both direct and indirect costs
• Contractual obligations that might be impacted
• Operational issues that might arise if you pursue an alternate configuration
• Long term field deliverability

Finally, consider if you are primarily concerned with reducing expenditures in the short term, or are looking for opportunities to optimize production. Maybe infrastructure spending will result in substantial production increases? While that would require a capital expenditure up front, the long term returns to efficiency or recovery may be well worth that investment.

In Summary

IHS Piper gives operators the tools to identify common operational issues and test potential corrective measures. Secondly, the software allows for testing several alternative field optimization scenarios to find the best possible solution in terms of minimizing costs and / or maximizing profitability. To determine the best field optimization strategy you should:

• Compare multiple optimization strategies against the Base Case
• Quantify the impact of any cost cutting measures on operational factors
• Evaluate revenue scenarios with CAPEX and OPEX for future profitability
• Contrast the economics or different scenarios with their operational impacts

For further reference:

http://blog.ihs.com/rpe-a-recipe-for-reliable-gathering-system-modeling
https://ihsmarkit.com/products/oil-gas-training-videos.html

One Petro - SPE No. 75946 "Case Study: Including the Effects of Stagnant Water in Gas Gathering System Modeling" by James Young, Ralph McNeil, Jeffery Knibbs

"An Effective Method for Modeling Non-Moving Stagnant Liquid Columns in Gas Gathering Systems" by R.G. McNeil, D.R. Lillico

Tracy Brenner, Principal Analyst/Researcher, IHS Markit Engineering

This article was published by S&P Global Commodity Insights and not by S&P Global Ratings, which is a separately managed division of S&P Global.