1. Features
It is a new designed product to substitute the existing slotted screen, wire wrapped screen and conventional low-end screens.
The product is composed of base pipe, high-density punched slot shroud and stainless steel support rings.
■ Filtering ability: the precisely punching technique is apllied and higher filtering ability is achieved. Side flow ports (90 degree inflow surface) are formed, with higher self-cleaning ability. Besides, the helical welding ensures the rigid filtering shroud, and effectively protects the filtering elements when running in hole.
■ Inflow ability: Effective across area is approximately 3-5 times as big as slotted screen..
■ Strength of base pipe: API tubing or casing is used as the base pipe, and helically perforated, to give higher base pipe mechanical strength than the slotted screen.
■ Corrosion resistance: High quality stainless steel and special welding technique are used, to eliminate the impacts of thermal stress and realizing excellent corrosion resistant ability..
■ Screen O.D. is smaller than equivalent casing collar, to give out great tripping-in performance.
2. Technical principle
Punched slot screen is a patented product on the basis of the API standard tubing or casing covered with the high-density stainless steel punched shroud which is welded on the tubing or casing. with support rings. The punched slots on the shroud are uniformly spaced to ensure the requirement for its precise filtering ability. Punched slot screen has higher filtering ability than the conventional wire wrapped screen and slotted screen, providing effective and reliable sand control.
3. Improvements
■ The wire wrapped screen has a less-strength filtering layer, enabling it liable to be deformed and corroded in horizontal well..
■ The slotted screen features small open area and low strength, so it is poor in corrosion resistance and jamming.
4. Cases history
The punched slot screen is well applied in various oilfields, It was used in Xinjiang, Tuha, Jilin, Daqing, and Huabei oilfields at home, and also in Sudan, Russia, South America, Middle East, etc. Totally more than 100,000m, were in hole.
5. Specifications.
Specifications for some composite screens.
|
O.D. of base pipe(in) |
Nominal size(mm) |
O.D.(mm) |
Effective slot length（m） |
Length(m) |
|
2⅜ |
60.3 |
72 |
46 |
3.2-13 |
|
2⅞ |
73 |
83 |
55.8 |
3.2-13 |
|
3½ |
89 |
109 |
67 |
3.2-13 |
|
4 |
101.6 |
110.5 |
76 |
3.2-13 |
|
4½ |
114.3 |
125 |
84.5 |
3.2-13 |
|
5 |
127 |
137 |
93.6 |
3.2-13 |
|
5½ |
139.7 |
150 |
102.7 |
3.2-13 |
|
6⅝ |
168.3 |
178 |
122 |
3.2-13 |
|
7 |
177.8 |
188 |
129 |
3.2-13 |
|
Effective length of slot is 3-5 times as long as the conventional slot, and can be customized. |
|
