During the operation of a pumping unit system, leakage is a common problem that affects production efficiency and equipment life. While "tubing leakage" and "pump leakage" are often mentioned, many people tend to confuse them. This article will systematically explain the differences between the two from four perspectives: definition, causes, impacts, and solutions, to help users quickly understand and diagnose the problem.
I. Definition:
Tubing leakage refers to the leakage of oil within the wellbore due to poor sealing at the tubing or joints during operation, preventing effective delivery to the surface.
Pump leakage refers to the failure of internal seals in downhole pumps (including rod pumps and tubing pumps), resulting in backflow or leakage of fluid within the pump chamber, reducing pumping efficiency.
II. Comparison of Main Causes：
| Classification | Oil pipe leakage | Pump leakage |
| Common Locations | Oil pipe body, joints, seals | Pump barrel, plunger, valve seat, seals |
| Typical Causes | Loose connections, pipe wall corrosion, aging or missing seals | Excessive clearance between plunger and barrel, worn valve ball/seat, aged seals, corroded parts |
| External Manifestations | Fluid loss along the wellbore, significantly reducing production | Normal stroke but no rise of liquid, reduced pump efficiency |
III. Impact on Production：
Tubing Leakage:
Liquid is directly lost in the wellbore, significantly reducing production.
In severe cases, it may contaminate the surrounding wellbore environment.
Pump Leakage:
Although the pumping unit is operating normally, liquid cannot be effectively lifted, significantly reducing pump efficiency.
Abnormal noise is generated in the pump chamber, which may even lead to equipment overload or safety hazards.
IV. Solutions:
Tubing Leakage:
Check tubing connections for tightness.
Replace aged or corroded tubing. Use high-quality seals (such as waterproof rubber rings and high-temperature-resistant gaskets) to improve sealing effectiveness.
Pump Leakage:
Inspect and replace worn parts such as the plunger, valve seat, and seals.
Replace the pump barrel or the entire pump if necessary.
In highly abrasive environments, choose pump materials made of wear-resistant alloys or special coatings to reduce wear.
V. How to Quickly Determine if the problem is tubing leakage or pump leakage?
If downhole fluid is significantly reduced but the pumping unit is operating normally, it is more likely a pump leakage.
If downhole fluid loss is severe and the tubing string shows signs of leakage, it is more likely a tubing leakage.
While tubing leakage and pump leakage from a pumping unit both result in reduced production, the fundamental difference is that tubing leakage and pump leakage in the former involve problems with the "transportation channel," while pump leakage in the latter involves a malfunction of the "wellbore pump itself." Regularly inspecting tubing seals and pump component wear can effectively prevent and reduce leakage.
FAQ:
1. What is the relationship between pump leakage and tubing pumps?
Pump leakage typically occurs in the downhole pump itself. Tubing pumps, a common type of oil well pump, are prone to pump leakage if the gap between the plunger and the barrel is excessive or if the valve seal is poor.
2. What are the common causes of oil tubing leakage in pumping units?
Main causes include aging tubing, loose joints, corrosion on the tubing wall, and aging or missing seals.
3. What are the common causes of pump leakage?
Pump leakage is often caused by wear of the plunger and barrel, damage to the valve ball and seat, aging of the seals, or corrosion of the pump body.
4. How to resolve oil tubing leakage?
Check the tubing connections for tightness, replace aging or corroded tubing, and use high-quality seals.
5. How to resolve pump leakage?
Worn parts such as the plunger, valve seat, and seals should be replaced. In severe cases, the barrel or the entire pump may need to be replaced. For wells with high abrasiveness, choose a tubing pump or rod pump made of wear-resistant material. 6. How can I prevent pump unit leakage?
Regularly check the tightness of the tubing and joints.
Regularly inspect the pump plunger and valve wear.
Use wear-resistant alloys or special coating materials in corrosive or sandy wells.