Introduction Of Commonly Used Mechanical Sand Control Screen Pipe

In order to solve the problem of sand emission in oil wells and water wells, sand control screen tubes are often used for sand control. Different anti-sand screen tubes have their own strengths in different application areas. Below is an introduction to several commonly used filter screen tubes for sand control in downhole wells:

1. Wire-wound screen tubes

Wire screen tube is an early use of sand screen tube, the use of trapezoidal stainless steel wire as raw materials, winding in a circular arrangement of a set of support wire welded into the winding wire and the support wire at each intersection are welded to form a higher strength of the whole, so it is also known as all-welded wire screen tube.

Features of wire-wound sieve tube:

(1) corrosion-resistant, long working life, adaptable, universal application

(2) Narrow slit outside and wide inside, with "self-cleaning" effect

(3) Large overflow area and high capacity.

2. Screen tube with center tube

The screen tube with center tube consists of a center tube (base tube), a wire-wound screen tube and a support ring. The center tube is made of drilled API-compliant casing or tubing. The screen tube with center tube is based on the original wire screen tube with holes in the center tube through the screen tube, the outer screen tube ends through the support ring solidly welded to the center tube.

Features of screen tube with center tube:

(1) Higher filtration precision

(2) Supported by the center tube inside, the overall strength and deformation resistance are greatly increased, which can resist the extrusion and deformation of the ground, and even when local deformation occurs, the gap in the pressurized part will not increase, thus improving the reliability of sand prevention.

3. Slit screen pipe

The slit screen pipe is a casing or oil pipe with some slits to allow the oil flow to pass through, and to stop the gravel of a certain diameter outside the screen pipe, so as to prevent the gravel from abrasion of the pump and jamming of the pump.

The earliest slit screen pipe was made by milling the casing on an iron bed with a saw blade milling cutter, and the size of the slit is affected by the width of the milling cutter. Processing the outer narrow and inner wide cut seam is time consuming and expensive, and the cost increases dramatically. With the emergence of laser processing and newer processing techniques, the processing and cost of slit screen tubes have changed significantly. Firstly, the design of the slit has been improved and a trapezoidal slit has appeared; secondly, the processing quality of the slit has been improved. The performance of cut seam screen tube is improved and the cost is further reduced, thus it is widely used.

Cut seam screen tube characteristics:

(1) Because it basically retains the solid outer wall structure of the original oil casing, it has the characteristics of high strength and not easy to deform.

(2) Widely used in inclined wells and horizontal wells, suitable for sandstone bottom layer with large median particle size.

4. Double-layer Prefilled Screen Tubing

Double-layer prefilled screen pipe mainly consists of outer screen pipe, inner screen pipe, prefilled gravel layer and center pipe. The concentric double-layer screen tubes are welded together and the annulus is tightly filled with gravel, which can form a multi-layer sand barrier to prevent formation sand from entering the production wellbore and play the role of sand prevention.

Characteristics of double-layer pre-filled screen tubes:

(1) Gravel filling and high-temperature cementing are completed on the ground, which is convenient for construction, short operation period and easy for post-treatment.

(2) High compressive strength, high permeability and large overflow area.

(3) Suitable for ordinary straight wells and inclined wells.