Special Applications for High Collapse Resistance Oil Casing

High collapse resistance oil casing is a specialized type of steel pipe used in oil and gas drilling, engineered to withstand collapse far better than conventional casing. It maintains structural integrity in extreme geological conditions and complex downhole environments. Its specialized applications are primarily in the following areas:
1. Ultra-deep Wells and high-pressure formations
Application scenario: In ultra-deep wells exceeding 8,000 meters or areas with abnormally high formation pressures, such as high-pressure gas reservoirs, the confining pressure is substantial, and ordinary casing is prone to being crushed.
Function: It resists ultra-high formation pressures and prevents wellbore collapse using high-strength steels like P110, Q125, and above, along with optimized wall thickness design.
2. Salt paste layer and creep formation
Application scenario: Formations such as salt rock and plaster mudstone exhibit plastic flow or creep characteristics, resulting in uneven loads on the casing.
Function: An anti-uniform load design, including features like ellipticity control and special coupling structures, prevents deformation or collapse caused by salt paste creep, ensuring the long-term stability of the wellbore.
3. Deepwater and deepwater drilling
Application scenario: Deep sea drilling in subsea high-pressure, low-temperature, and complex ocean current environments demands exceptional anti-squeezing performance from the casing.
Function: By combining high-strength materials and anti-corrosion coatings, such as duplex stainless steel and nickel-based alloys, the casing can withstand the dual damage from deep sea high pressure and corrosive media.
4. Shale gas and unconventional oil and gas development
Application scenario: Shale gas horizontal wells require extensive hydraulic fracturing, and frequent high-pressure operations may lead to casing damage.
Function: An anti-internal pressure and anti-collapse composite reinforcement design is employed to endure alternating loads during fracturing operations and minimize the risk of casing failure.
5. High-temperature geothermal Wells
Application scenario: Geothermal wells often encounter high temperatures (over 200°C) and thermal cycling stress, which can cause thermal expansion or yield in the casing.
Function: High-temperature resistant steels, such as 13Cr and Super 13Cr, are selected, and thermal stress distribution is optimized to prevent a decline in extrusion resistance at high temperatures.
6. Sulfur-containing acidic environment (H2S/CO₂)
Application scenario: In oil and gas fields with high hydrogen sulfide or carbon dioxide content, corrosion can significantly diminish casing strength.
Function: By using sulfur-resistant materials, such as L80-13Cr and P110 sulfur-resistant steel, in conjunction with anti-collapse design, localized collapse resistance due to corrosion is avoided.
7. Complex geological structure area
Application scenario: In active fault zones or earthquake-prone areas, the formation stress changes dramatically.
Function: Dynamic anti-collapse design, such as utilizing high-toughness steel, absorbs the energy from formation stress fluctuations to prevent sudden collapse.
8. Old well restoration and secondary completion
Application scenario: Sidetracking or secondary completion is necessary in old wells due to casing aging or changes in the formation.
Function: As an outer casing repair solution, it provides additional anti-squeeze support for the original wellbore and extends the well’s lifespan.