3 Types of Deepwater Borewell Casing Pipe

Deepwater borewell casing pipe is an important equipment used to protect the borewell wall and prevent collapse and pollution. Deepwater borewell casing pipe can be divided into many types according to the material and manufacturing process. Below, we will introduce these types and their characteristics in detail.

Seamless pipe

Seamless pipe is a tubular material made of a whole piece of metal with no seams on the surface. This kind of casing pipe has high strength and pressure resistance and is suitable for high-pressure environments such as deepwater borewells. The manufacturing process of seamless steel pipe is complex and the cost is high, but its excellent performance makes it the first choice for high-end water borewell casing pipe. Its core advantages are:

1. Compressive strength: up to 550MPa or more (API standard)

2. Pressure resistance: The pressure bearing capacity exceeds 30-45% of the same specification welded pipe

3. Process characteristics: normalizing/tempering heat treatment is required to eliminate residual stress

4. Typical applications: ultra-deep borewells (>500m), high mineralization formations, geothermal borewells and other harsh environments

Straight seam resistance welded steel pipe

Straight seam resistance welded steel pipe is a casing pipe made by welding steel plates into a tubular shape through resistance welding technology. This casing pipe has a simple manufacturing process and low cost, and is widely used in various water borewell projects. Although its strength and pressure resistance are slightly lower than seamless steel pipes, it is sufficient to meet the needs in general water borewell applications. Its core advantages are:

1. Welding efficiency: production speed can reach 20-30 meters per minute

2. Cost advantage: 40-60% lower procurement cost than seamless pipes

3. Quality improvement: modern online eddy current detection achieves 100% weld monitoring

4. Applicable scenarios: medium and shallow freshwater borewells (<300m), temporary water intake projects

SSAW steel pipe

SSAW steel pipe is a steel pipe manufactured using submerged arc welding technology, which is characterized by a spiral weld. This type of casing pipe has high production efficiency and moderate cost, and is suitable for large-scale water borewell engineering construction. The performance of SSAW steel pipe is between seamless steel pipe and straight seam electric resistance welded steel pipe, and is a cost-effective choice. Its core advantages are:

1. Structural characteristics: spiral welds make stress distribution more uniform

2. Diameter-to-thickness ratio: up to 100:1, 30% better than straight seam pipes

3. Engineering benefits: single pipe length can reach 12-18 meters, reducing on-site joints

4. Best application: large-scale centralized water supply projects, riverside water intake projects

The following is a comparison table of various deepwater borewell casing pipes:

Selection suggestions

When selecting deepwater borewell casing pipes, it is necessary to comprehensively consider engineering needs, budgets and performance requirements:

1. Seamless steel pipes have excellent performance but high costs, which are suitable for scenes with extremely high strength and pressure resistance requirements, in drill pipe and octg pipe, similar manufacturing processes are often used to ensure the quality of oil and gas projects that require high precision and high strength.

2. Straight seam electric resistance welded steel pipes have a low cost and are suitable for projects with limited budgets and low performance requirements.

3. Spiral seam submerged arc welded steel pipes are a cost-effective option, suitable for large-scale water borewell projects. For projects that require a large number of casing pipes, they can not only ensure a certain quality but also control costs.

Summary

As the core protection system of water borewell projects, deepwater borewell casing pipe plays a key role in maintaining the stability of the borewell wall, blocking formation pollution and ensuring water supply quality. The reasonable selection of deepwater borewell casing pipe not only affects the construction efficiency, but also affects the later operation and maintenance costs and water quality safety. It is recommended to communicate closely with pipe suppliers and construction units during the design stage, and make comprehensive decisions based on geological reports, borewell depths, water quality and other factors.

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