This blog is the second in a series that addresses the five main technologies for manifold operation and control. Read below for a brief write-up on hydraulically-operated high-pressure manifolds.

While manually-operated manifolds are quite common in oil & gas applications today, the second most popular technology for operating manifolds is hydraulics. Hydraulically-driven manifolds have been around for decades and they have a few distinct advantages over their manually-operated counterpart: safety, power density, user-friendliness, and reduction in manpower . Manually-operated manifolds require a technician to be at the manifold skid, potentially putting the technician in harm’s way. They must also use a gear operator or valve bar to rotate the plug and choke valves. This is a labor-intensive process, especially if being performed with high pressure, high velocity media flowing through the manifold. Incorporating a hydraulic power unit (HPU) and hydraulic actuators dramatically reduces the manpower needed to operate the manifold.

Advantages

  • High Power Density: high pressure of hydraulics provides for compact, lightweight actuators
  • User-friendly Operation: individual valve functions are easily controlled with manual handles or push buttons
  • Reliability: robust components and hydraulic conductors
  • Safety: HPU or hydraulic control panel can be located away from the high pressure, high velocity manifold
  • Hazardous Certification: system incorporates low-cost components that meet hazardous area requirements such as air-driven pressure intensifiers, hydraulically-piloted directional control valves, and hydraulically-operated plug and choke valves
  • Operational Costs: hydraulic automation drives down labor costs needed to operate the manifold

Disadvantages

  • Operator Mobility: HPU and/or hydraulic control panel are tethered to the manifold
  • Maintenance: fluid conditioning/filtration requires routine management
  • Environment: high potential for leaks due to numerous hydraulic components and connections (can be mitigated with drip pans and environmentally-considerate hydraulic fluids)
  • Footprint: hydraulic equipment such as the control panel, HPU, and fluid conductors increases size, space, and weight consumption on work site
  • Startup: additional time to connect manifold with the remote hydraulic control panel, HPU, and numerous hoses
  • Installed Cost: the additional equipment and maintenance requires a greater capital expenditure compared to manually-operated manifolds

Hydraulically-operated manifolds are a field-proven technology embraced within the well stimulation market. Hydraulic fluid power is reliable, user-friendly, and provides ease of automation for the manifold’s plug and choke valves. While reducing manpower is a strong benefit for manifold operators, one must also consider the bulkiness and weight of the added hydraulic equipment. However, these items can be remotely placed such that a technician can control the manifold from a safe distance.

The following blogs in this series will cover the three remaining operating technologies (pneumatic, electric, wireless).