An oilfield tubing anchor plays an important role in safe and efficient production operations. Not only does it provide stability to the tubing string, it also prevents unwanted vertical and lateral movement. This is particularly the case in highly deviated and high productivity wells.
In wells that utilize rod pump systems, the use of an oilfield tubing anchor can provide several advantages. These advantages contribute to increased production efficiency, lower operating expense (OPEX) and higher safety. Some key benefits include:
- Higher pump efficiency – By stabilizing the tubing string, an oilfield tubing anchor can improve the efficiency of the rod pump system. In wellbores with tubing that is freely suspended, tubing can elongate on the pump down stroke. At the same time, the rods contract (i.e., shorten). Conversely, on the up stroke, the tubing contracts and the rods elongate. This effectively reduces travel distance, which in turn, decreases production. An oilfield tubing anchor prevents such a condition from occurring.
- Minimizes wear on rods, tubing, casing and the pump – The continuous cycle of elongating and contracting increases the risk of tubing buckling. In such cases, the tubing string can bend and/or coil, causing it to rub against the rod and/or the casing. This motion causes wear to the casing, the tubing and the pump barrel. In turn, the risk of early failure is heightened, as is the potential need for costly interventions. The added friction also necessitates more power for lifting, which increases OPEX. In the case of deep, highly productive wells, if the wear is excessive, the tubing can part and cause an expensive fishing job.
- Maintains downhole alignment – An oilfield tubing anchor helps maintain the alignment of the tubing string within the wellbore. Proper alignment is crucial for the efficient operation of the rod pump system. Misalignment can lead to pump component damage and poor pump performance.
- Reduces vibrations and tubing whipping – A well-designed oilfield tubing anchor can help dampen vibrations and reduce tubing whipping, which can occur during pump operation. This is important for safety reasons and to prevent damage to the tubing and other downhole equipment.
Additional Benefits with the TechTAC® Slimline®
While most oilfield tubing anchors can deliver the benefits listed above, the unique design of the Slimline® TAC provides additional advantages. In particular, it can help reduce the occurrence of gas locking.
In wells with high gas-to-liquid ratios, gas tends to migrate along the annulus between the tubing and the casing. Standard tubing anchors can create a seal or barrier that causes restrictive turbulent flow, thereby increasing the risk of gas entering the rod pump. When a pump gas locks, the hydrostatic pressure of the column of fluid and gas above the traveling valve of the plunger is greater than the compressed pressure of the gas below the plunger in the barrel of the pump. The end result is little or no fluid entering the tubing, and potentially, a complete halt in fluids production.
With the increased flow area between the anchor outside diameter (OD) and the casing ID (up to 245% increase over the standard anchor), the TechTAC’s Slimline® is an oilfield tubing anchor that allows gas to flow freely up the casing/tubing annulus rather than through the sucker-rod pump. With its tapered design and smaller diameter, a laminar flowpath is created, reducing the risk of gas interference.
Conclusion
In summary, using an oilfield tubing anchor in conjunction with a rod pump system is highly advantageous. It contributes to greater pump efficiency and prevents excessive wear on the tubing, casing and other critical downhole components.
For more information on TechTAC’s line of tubing anchors – which include standard B2 TACs, quarter-turn anchors and the patented Slimline® – visit the anchors product page on TechTAC’s website.
