Introduction
DPH Engineering are Authorized Distributors of downhole sucker rod pump seals. There are two basic types of subsurface pumps, the tubing pump and the insert pump. The tubing pump barrel is threaded directly onto the bottom of the production tubing, and is installed near the bottom of the well immersed in the oil within the well casing. The plunger is run into the tubing on the sucker rod string. Generally a standing valve puller is run between the bottom of the plunger as well as the separate standing valve. This makes the removal of the standing valve optional when pulling the sucker rods and plunger. The plunger, traveling valve, and standing valve can be serviced simply by pulling the rods, but it requires removal of the tubing to service the pump barrel.
An insert pump is run into the well on the rods as a complete unit. A seating assembly on the pump engages a seating nipple on the tubing when the pump is run in, or installed. After the well has pumped up, the additional pressure of oil in the tubing combined with the flow line pressure holds the pump firmly in place. The entire rod pump is removable, and therefore may be serviced merely by pulling the sucker rod string.
Specifications:
| Nominal size | Φ16（5/8″） | Φ19（3/4″） | Φ22（7/8″） | Φ25（1″） | Φ29（11/8″） |
| Diameter of rod | 15.88+0.18-0.36 | 19.05+0.20-0.41 | 22.23+0.20-0.41 | 25.40+0.23-0.46 | 28.58+0.25-0.51 |
| （0.625+0.007-0.014） | （0.750+0.008-0.016） | （0.875+0.008-0.016） | （1.000+0.009-0.018） | （1.125+0.010-0.020） | |
| Shoulder diameter of pin end | 31.8+0.13-0.25 | 38.1+0.13-0.25 | 41.3+0.13-0.25 | 50.8+0.13-0.25 | 57.2+0.13-0.25 |
| （1.250+0.005-0.010） | （1.500+0.005-0.010） | （1.625+0.005-0.010） | （2.000+0.005-0.010） | （2.250+0.005-0.010） | |
| Width of wrench square | 22.2（0.875） | 25.4（1.000） | 25.4（1.000） | 33.3（1.313） | 38.1（1.500） |
| Length of wrench square | 31.8（1.250） | 31.8（1.250） | 31.8（1.250） | 38.1（1.500） | 41.3（1.625） |
| Length of sucker rod (API Standard) | 508（20） | 508（20） | 508（20） | 508（20） | 508（20） |
| 1118（44） | 1118（44） | 1118（44） | 1118（44） | 1118（44） | |
| 1727（68） | 1727（68） | 1727（68） | 1727（68） | 1727（68） | |
| 2337（92） | 2337（92） | 2337（92） | 2337（92） | 2337（92） | |
| 2946（116） | 2946（116） | 2946（116） | 2946（116） | 2946（116） | |
| 7518（296） | 7518（296） | 7518（296） | 7518（296） | 7518（296） | |
| 9042（356） | 9042（356） | 9042（356） | 9042（356） | 9042（356） | |
| Length of sucker rod (Chinese Standard) | 900，1400，1900, | 900，1400，1900, | 900，1400，1900, | 900，1400，1900, | 900，1400，1900, |
| 2400,2900,3400, | 2400,2900,3400, | 2400,2900,3400, | 2400,2900,3400, | 2400,2900,3400, | |
| 79,009,900 | 79,009,900 | 79,009,900 | 79,009,900 | 79,009,900 | |
| Upset flange diameter | 31.1+0.13-3.17 | 35.7+0.13-3.17 | 38.1+0.13-3.17 | 48.4+0.13-3.17 | 55.6+0.13-3.17 |
| （1.219+0.005-0.125） | （1.406+0.005-0.125） | （1.500+0.005-0.125） | （1.906+0.005-0.125） | （2.188+0.005-0.125） | |
| AR±3.2（±0.125） | 47.6（1.875） | 57.1（2.250） | 66.7（2.625） | 76.2（3.000） | 85.7（3.375） |
| CR+1.59-0.40 | 3.2（0.125） | 3.2（0.125） | 4.8（0.188） | 4.8（0.188） | 4.8（0.188） |
Types of Pumps:
API recognizes two main types of pumps: Rod and Tubing. Rod pumps also are called insert pumps because they are run (inserted) in the production tubing. Tubing pumps are so named because the working barrel of this pump is coupled with the production-tubing string.
There is a wide range of plunger (or pump-bore) sizes standardized by the industry. The API pump-bore sizes that are currently available range from 1 1/16 to 3 3/4 in. in diameter. This 1 1/16-in. size has been added back in the latest edition of the standard. API pumps and nomenclature
Selection of Subsurface Rod Pumps :
Pumps for sucker-rod lifted wells should be selected on the basis of numerous variables that are provided by the well, the operating conditions, and the life of the pump. The main variables to consider are as follows:
- Well depth
- Bottomhole temperature
- Fluid viscosity
- Amount and size of particulates in the
- produced fluids
- Produced-fluids corrosivity
- Required production rate vs. pump capacity
- Fluid-specific gravity
- Casing/tubing size
- Well-completion type
- Gas/liquid ratio (GLR)
- Pump-intake pressure vs. fluid bubblepoint
- Spare/surplus pumps and components
- New purchase and repair costs
These variables influence:
- Stresses on the pump
- Type of Pump Used
- Component metallurgy
- Pump size
- Internal-fit tolerance
- Ability to handle solids/gas
Discussing these parameters with the pump manufacturer and local pump shop should help determine the proper pump to ensure acceptable pump life.
Pump Operating Problems And Solutions :
There are four common ways subsurface rod pumps are abused. These problems may also be applicable to other downhole pumps, and thus, these related solutions probably are applicable to other artificial-lift techniques. The four common abuses follow:
- Overpumping the well
- Gas interference
- Pump hitting up or down
- Trash entering the pump
Because the recommended pump-displacement design is for the pump to have greater capacity than the well, an overpumping condition may occur if the well is not properly controlled.
