Above: Above: Image 1. A large bypass oil filtration system installed on a typical hydraulic fracturing truck. These systems have historically been used for engines that power the pumps, compressors and other equipment in E&P activities. Winter conditions present unique hazards and difficulties for engines that power the pumps and other equipment of energy exploration and production (E&P) companies—from sub-freezing temperatures to snow and ice. During the past few years, upstream companies have gotten the message that the best way to keep engines operating successfully through all types of weather is by using a proactive approach to keeping engine oil clean and equipment properly lubricated. Substantial bottom-line costs savings, based on specific operations that have contributed significantly to the bottom line of some corporations, and positive word of mouth have led to an upsurge in the use of bypass oil filtration systems by several large and mid-size production companies.
Changes in Maintenance Practices
Until recently, scheduled maintenance, also called preventive maintenance, was the standard for the vast majority of E&P companies. Under that model, engine checks were conducted on a schedule that was based on when the engine manufacturer said the oil needed to be changed. This method was adequate if the conditions under which the engine operated were ideal. That kind of thinking is often more utopian than pragmatic. Preventive maintenance is a step better than reactive maintenance, which meant replacing the oil or the oil filter in an engine after the engine failed. That delayed the completion of drilling projects and could cost tens of thousands of dollars in unexpected and often unnecessary downtime. The latest concept for keeping engines running clean and healthy is called condition-based maintenance (CBM). CBM is designed to extend the life of the engine by eliminating the root cause of equipment failure and constantly anticipating the needs of the equipment. Although end users might expect CBM to be more expensive, at least initially, maintenance costs are actually much lower, even at the beginning. CBM allows for:
- Safe extensions of oil drains and overhauls
- Alerts issued only if something needs to be addressed immediately, before it becomes a critical issue
Two examples of CBM in action are engine bypass oil filtration and oil analysis.
Bypass Oil Filtration & Oil Sampling
Bypass oil filtration slowly diverts a small amount of lubricating oil from the engine, cleans it of solid, liquid and gaseous contaminants—down to below one micron in size—and allows for base additives to be replenished. This maintains the viscosity and oil chemical balance, which keeps lubricating oil clean and contaminant-free. Clean, contaminant-free oil can perform its designed job—cooling, lubricating and sealing the engine—for longer periods of time. The clean oil is then fed back into the engine, and nothing further must be done until the next scheduled service interval. At that time, an oil sample is taken and the disposable filter is replaced. Drawing the oil sample and changing the replacement filter is completed within a matter of minutes while the equipment operates, if necessary, which results in no downtime.
Oil analysis (see Images 2 & 3) monitors the overall health of the engine and lubricating oil by continuously checking the condition of the oil—including the viscosity and engine wear metals. Engine oil can remain in active use for as long as the oil sample indicates that the oil is suitable for continued use.
A Colorado-based natural gas pipeline operator has used oil bypass filtration for more than eight years—primarily to increase time to overhaul, which greatly reduces the life-cycle cost of the engine. Its fleet is comprised of 61 natural gas compressors. All use a large oil bypass system (see Image 4), which can micro-filter oil sump capacities of 85 gallons (322 liters) and is designed to be used in multiples in engines that can hold up to 450 gallons (1,703 liters) of oil. This system easily handles operations in demanding environments 24 hours per day and seven days per week. Onsite, every component of an engine is inspected as it is taken apart for an overhaul. At the first overhaul interval after installing the system, the engine was torn down, and all the components were inspected. Management noted how clean the parts were. From that point on, the company has extended its overhaul intervals by approximately 25 percent, or 10,000 hours. One E&P operator first tested the bypass oil filtration system to see how it could improve the company’s maintenance practices and reduce its overall operating costs. Because of the E&P company’s operations, the supplier of the bypass systems provided different sizes designed to match the specific engines and operation parameters, which included the largest model. Monitored results revealed that oil drain intervals were being extended to 2,500 hours from 500 hours, a five-fold increase. Following the test, the client outfitted more than 1,500 bypass filtration systems on its rigs throughout all divisions of the company. Moreover, the company expanded its maintenance practices, using a sensor that provides real-time feedback—on a software-based platform—as the engine operates, to avoid the need to shut down operations. The international division, which alone operates about 400 engines, experiences millions of dollars in annual savings on reduced oil purchases and disposal costs. These savings are based on 370,000 fewer gallons of engine lubricating oil and a reduction in maintenance and man-time of more than 5,500 hours.
Expansion into Other Oilfield Services
Given the success of condition-based maintenance using bypass oil filtration and oil analysis, the next step was to apply this type program to other oilfield service entities. During the past year, this combination has spread to other related operations and is now being installed on trucks used in hydraulic fracturing operations (see Image 1) with field results similar to those of the E&P client. The Environmental Protection Agency estimates that more than 15 percent of U.S. natural gas production is from shale gas extraction using hydraulic fracturing. More equipment is coming online to handle this rapidly expanding type of production. Typically, the engines used on hydraulic fracturing trucks will run 24 hours per day for four to five days at a time in a stationary setting before shutting down and moving to the next job. A normal running year consists of approximately 4,000 hours per year. Cyclical use tends to create more contaminants, but operating these massive engines is critical for the success of the operation. Whether engines are mounted on permanent foundations or mobile units, a sound maintenance program is a crucial support in sustaining well drilling and construction standards. Trucks engaged in the non-stop activity of well servicing carry a responsibility that cannot and will not wait for oil-related maintenance repairs. Future contracts will often be based on reliability and risk-containment on past and current jobs. The combination of bypass oil filtration and oil analysis will ensure that equipment operates safely, efficiently and contaminant-free.