In the oil and gas industry, maximizing efficiency and safety are paramount. One of the critical components that contributes to these goals is the oilfield anchor. Often called a tubing anchor, tubing anchor catcher or TAC, this relatively small piece of equipment plays a significant role in ensuring the smooth operation of oil wells. This post will delve into the purpose and benefits of oilfield anchors, highlighting their importance in the extraction process.
Purpose of Oilfield Anchors
Oilfield anchors are mechanical devices installed in oil wells to stabilize the tubing string. These devices prevent the string from moving up and down due to the forces exerted by the well’s fluid dynamics. Forces like pressure changes associated with the extraction process can cause the tubing to move if not properly secured. The primary purposes of oilfield anchors are:
- Stabilization of Tubing. The primary function of oilfield anchors, or tubing anchors, is to hold the tubing string firmly in place. This stability is crucial to ensure the integrity of the well and the accuracy of the extraction process.
- Mitigation of Tubing Movement. In the absence of an oilfield anchor, the tubing string can move vertically. This movement can lead to equipment wear, operational inefficiencies, and safety hazards. Oilfield anchors mitigate these risks by preventing such movements.
- Enhancement of Production Efficiency. By stabilizing the tubing, oilfield anchors help maintain consistent production rates and reduce downtime caused by maintenance or equipment failure.
Benefits of Oilfield Anchors
The use of oilfield anchors in oil wells brings numerous benefits, all contributing to the efficiency, safety and cost-effectiveness of oil extraction. Here are some key benefits:
- Reduced Wear and Tear. Oilfield anchors, or tubing anchors, minimize the vertical movement of the tubing string, which significantly reduces wear and tear on both the tubing and the associated equipment. This reduction in mechanical stress extends the lifespan of the well components, leading to lower maintenance costs and fewer operational interruptions.
- Enhanced Safety. The stabilization provided by oilfield anchors enhances the overall safety of the well operation. Preventing uncontrolled tubing movement reduces the risk of accidents and equipment failures, protecting both the workforce and the environment from potential hazards.
- Improved Pump Efficiency. In wells that use rod pumps or other artificial lift systems, oilfield anchors improve the efficiency of the pump by keeping the tubing string stable. This stability ensures that the pump operates at optimal performance, leading to better extraction rates and reduced energy consumption.
- Cost Savings. The combination of reduced maintenance, extended equipment lifespan, and improved operational efficiency translates to significant cost savings for oil companies. By investing in quality oilfield anchors, companies can achieve a higher return on investment through more reliable and efficient well operations.
- Consistent Production. Stabilized tubing helps maintain a steady flow of oil, ensuring consistent production rates. This consistency is crucial for meeting production targets and maximizing the profitability of the well.
Which Oilfield Anchor is Best for Your Well?
Many varieties of oilfield anchors, or tubing anchors, are sold to accommodate the needs of different well designs. No matter the style, however, the anchor’s primary purpose remains stabilizing the production string. For decades, the industry has relied on standard B2 tubing anchor catchers to perform this important function. Unfortunately, standard B2 anchors can also inhibit a well’s production. A study by Echometer Company examined the production rates of 11 oil wells. Each well had high fluid levels and the pump intake was located below the perforations. Yet despite these seemingly favorable conditions, nine of the wells showed a pump fillage rate of less than 90%.
According to the report: “In these wells that exhibited high fluid levels … the fluid distribution in the wellbore below the liquid level was not uniform. The wellbore in the vicinity of the pump intake was primarily filled with gas with a minimal volume of liquid. …The presence of a tubing anchor set high above the pump intake is considered to be the main cause of this uneven distribution of fluids in the wellbore.
“The particular tubing anchor used in these wells provides a flow area of about 2.9 square inches between the body of the anchor and the casing compared to a flow area of 14.4 square inches between the casing (4.892-inch ID) and the tubing (2.375-inch OD). The small flow area could increase the velocity of the upwards flowing gas to the point where it would be difficult for liquid present in the upper part of the annulus to flow downwards past the depth where the tubing anchor is set. The anchor would essentially act as a choke and also cause an increase of the annular back pressure.”
In other words, the tubing anchor itself was restricting the flow of gas up through the annulus of the well. The gas that did escape had an increased velocity. That velocity made it difficult for fluid above the anchor to fall past it and reach the pump. In turn, the fluid around the pump had a high gas content, making highly efficient production impossible.
An Alternative to the Traditional Oilfield Anchor
TechTAC®, a premier supplier of oilfield anchors, offers an alternative to the “choke” created by a traditional anchor. The company’s patented Slimline® Tubing Anchor Catcher improves the flow-by capacity of fluid in the annulus by as much as 245% over a standard B2 anchor. That increased flow-by area allows gas to more easily flow up the well, rather than being trapped around the pump. The Slimline® also features tapered flow deflectors on the top and bottom. That tapered design, along with the anchor’s reduced OD, virtually eliminates the risk of sediment or paraffin building up on top of the anchor. As such, it can be safely set above, in or below the perforations, depending on the well design.
One U.S.-based oil and gas company saw these benefits firsthand. “We were having trouble with high fluid levels because the fluid could not sufficiently drop past a standard anchor,” said a senior completion foreman with the company. “Those elevated levels were causing some pump failure due to gas locking. We tried the Slimline TAC, and in every well we tested, fluid levels were at or just above the anchor.”
Conclusion
In the complex environment of oil extraction, every component plays an important role in ensuring the success of the operation. Oilfield anchors are indispensable for stabilizing the tubing string and enhancing the overall efficiency and safety of oil wells. Their ability to reduce wear and tear, improve pump efficiency and provide significant cost savings make them a critical investment for any oil extraction operation.
Despite the benefits, standard B2 anchors can also create additional obstacles to efficient production. That’s why TechTAC® created the Slimline® TAC. The anchor’s patented design not only stabilizes the production string, but it also allows gas to flow around the TAC and sediment to drop past it. This increased annular area positively impacts production and greatly reduces instances of gas locking and stuck anchors. To see TechTAC’s complete line of tubing anchors, or to get a quote, contact the TechTAC® team today!
