The oil and gas industry is currently facing a dilemma over the concerns raised on the use of open pits to store fluid waste from the drilling process. The most prominent concerns raised are the massive costs associated with their construction, the environmental hazard they pose and the resulting excessive drilling fluid costs. Closed-loop waste management systems, however, are beginning to phase out the open pits offering a cost-effective and efficient solution that introduces the recycling of drilling fluid and proper disposal of solid waste.
What is a Closed-Loop System?
A closed-loop drilling fluid system uses a series of storage tanks and solids control equipment to remove drill cuttings from the drilling fluid once it has carried them out of the wellbore during the drilling process. By removing these cuttings quickly and efficiently, an operator can increase the life of the drilling fluid and minimize waste, both of which have a significant impact on overall drilling costs.
How it Works
We employ chemical and mechanical processes to remove the solid wastes and treat the drilling fluid. Upon exiting the wellbore, the solids-laden drilling fluid first passes a series of rig-operated shale shakers that remove large cuttings. For oil-based and synthetic-based fluid systems, these cuttings then proceed to our four-panel high G drying shakers where they are dried further and more fluid is recovered. The recovered fluid is directed to a steel catch tank where it waits to be further refined by our enhanced centrifuge package, which is capable of removing very fine particle solids (down to 9 microns). Both the remaining liquid and solid waste are then removed from the tanks with a front-end loader while the clean liquid is returned to the rig’s active drilling fluid pit system.
Traditional Options
In the traditional drilling process, once the drilling fluids have been circulated in the wellbore, the waste is deposited in earthen pits dug close to the wellbore. In most cases, the law requires that reserve pits are lined with watertight material or placed in areas of impermeable clay soil or a hardpan. However, the design, construction and performance requirements are not standardized across all states, making compliance difficult for many exploration and production companies.
Disadvantages of Traditional Reserve Pits
- – Holes can sometimes overflow during rains, causing floods and spills
- – Improperly lined reserve pits may expose the soil, animals, groundwater and surrounding environments to hazardous fluid waste and other chemicals
- – Closed reserve pits can cause long-term human health hazards and environmental exposure to pollutants.
Cost Benefits of Closed-Loop Systems
Based on research by Oil & Gas Accountability Project (OGAP), there is a 43 percent saving on costs by using the closed-loop system instead of the traditional methods. The cost savings come from:
Saving on Water Transportation Cost
An estimated 300 truckloads of water used for drilling each well has to be carried by large tankers. Because the well pad is not typically located near the water source, the transportation costs can be expensive. The closed-loop method allows for reuse of the water and can reduce water consumption by as much as 50 percent, therefore minimizing water transportation costs.
Saving on Wellsite Construction Costs
To prevent ground water seepage, reserve pits require watertight plastic lining materials, which, along with fencing materials, make the construction of these pits expensive. Traditional pits also require more acreage that can be expensive to acquire. The closed-loop system eliminates these construction expenses and, if optimized properly, can significantly decrease the overall cost of the oil and gas drilling process.
Saving on Dilution Costs
Costs associated with drilling fluids can vary significantly based upon the chemical properties needed for each individual well. As fluid usage increases, so does the amount of chemicals needed to maintain the appropriate fluid properties. Expenses associated with these chemicals impact the overall drilling cost.
Additional Savings for Oil-Based and Synthetic Fluids
Oil-based fluids, especially diesel based fluids, are much more expensive to maintain than water-based fluids. Not only is diesel fluid more expensive than water, so are the costs associated with disposing of its waste. Just like with water, using a closed-loop system will reduce the amount of oil-based fluid dilution and oil-based fluid waste.
Cost Monitoring
The closed-loop system allows E&P companies to track, with greater accuracy, the volume of drilling fluid used and the volume of waste generated. Improved tracking leads to better planning and improved cost reduction efforts.
Advantages of Closed-Loop Fluid Waste Management Systems
- – Closed-loop systems reduce reserve pit construction costs and water transportation costs.
- – Traditional methods require more acreage than closed-loop systems.
- – Conventional drilling methods use a lot of water and drilling fluid while closed-loop methods reuse the water, reducing the amount used by about 50 percent.
- – Closed-loop systems reduce the environmental hazards brought about by putting waste in traditional-style pits.
- – Closed-loop systems reduce fluid and chemical costs associated with dilution.
Changing the Game with Aerion’s Fluid Waste Management Systems
Aerion provides the best fluid waste management solutions. We are committed to providing high quality closed-loop systems that exceed customer expectations in cost-effectiveness and performance. Contact us today to proactively manage your drilling needs.