Proper skid-assembly installation can guarantee reliable VRU performance.
by Glenn Webb, Blackmer
April 1, 2015
All reciprocating-type compressors produce shaking forcesImage 4. All reciprocating-type compressors produce shaking forces. If the compressor is not installed correctly, those shaking forces will create vibrations that can harm the performance of the compressor and VRU.

At one company, a number of reciprocating compressor oilfield VRU installations were not operating at peak performance. Investigation revealed that the issues were not caused by any individual VRU components; instead, the skid assemblies were not properly designed and/or installed. Prolonged operation with an improperly designed skid or poor foundation can damage the compressor and compromise the VRU’s overall operational effectiveness and reliability.

Proper skid assembly is paramount because reciprocating compressors can produce unbalanced forces when operating at peak speeds. The following steps can ensure proper skid assembly:

  • The compressor should be anchored to a baseplate (or skid) that is at least four times the compressor’s weight.
  • The baseplate with the compressor and other VRU components should be bolted to a concrete slab or pad.
  • The concrete slab or pad should be placed on a level surface.
  • The pad should be prepared and graded, if necessary.
  • The baseplate skid should never be installed on non-compacted soil.

Following these simple rules for skid-assembly installation can minimize the amount and severity of the vibration that occurs during compressor operation, which helps optimize the VRU’s performance and longevity.

A reciprocating compressor in an oilfield applicationImage 5. A reciprocating compressor in an oilfield application


In the fast-growing oil and gas industry, speed, portability and reliability are key factors in optimizing production times and the bottom line. There is now an almost constant need for the installation of VRUs in the oil field as production operations continue to accelerate.

VRUs are complex, highly engineered systems designed for reliable performance in harsh operating conditions. However, the oil field’s rugged terrain, combined with the need for rapid deployment and a reduction in site-time preparation, can compromise VRU installation. Original equipment manufacturers and system fabricators who take the time to install the VRU’s skid assembly correctly will find that any subsequent time and cost incurred because of downtime, repairs and maintenance will be greatly reduced.