BLOG: Through The Pipeline

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The growing abundance of natural gas in North America from unconventional sources is driven in part by the gas industry migrating from pure natural gas to oil and Natural Gas Liquid (NGL) development.  Oil shale oil & gas plays are being developed in North American states and provinces not necessarily familiar with gas gathering and processing. 

I’ve been asked by gas compression technical specialists to share observed practices which may result an improved success with reciprocating engine-driven compression with the oily gases which are present in the oil shales rich in NGLs.  Better practices with engine-driven gas compression installations, their start-up and commissioning and maintaining effective production may be helpful to all. 

Although the nature of a blog forum doesn’t lend itself to these many subjects all at once, we can begin with installation fuel system design, fabrication and construction. Effective fuel water separation and fuel particulate filtration is especially important in the oil shales. Although a reciprocating engine can handle large quantities of pure water when under constant load, the challenge to the engine is not the water but the gases which may be in solution in the water. Elimination of the vast majority of the water from fuel helps control the fuel quality of gases the engine receives.   

Fuel filtration down to 1 micron is important to prevent debris from pipeline construction and repair is critical to prevent damage to pressure regulators, control valves, carburetors or fuel actuators. 

Insuring hydrocarbon liquids do not enter the engine’s fuel system is an important measure which should be considered in the NGL areas. A two-prong approach can minimize condensate:  a coalescing filter with an automatic drain and collection tank; and an engine coolant fuel heater. The coalescing filter protects the engine and pays for itself in additional NGL collection for sale. Fuel heaters should be considered when the total amount of hydrocarbons C4H10 and larger are greater than 3% by volume. Heaters are available and may use the engine coolant system to heat the fuel after the coalescing filter before the particulate filter. More information on fuel filters and heaters is available in the Fuels / Fuel Systems portions of the Gas Engine Application & Installation Guides presented in the Reference Guides section under the Reference Materials Tab on the left side of the GERP home page. 

If not familiar with GERP (Gas Engine Rating Pro) please request a copy from the bottom of the following page: http://catoilandgas.cat.com/industries/gas-compression/gerp.  Its easy to find, simply seek “GERP Caterpillar” in an internet search engine and select the entry mentioning Caterpillar Oil & Gas.

What are you finding in the oil shale installations relative to fuel system designs and installations?