Geological seamless steel pipes are seamless steel pipes designed and manufactured for complex geological environments such as geological exploration, drilling and underground engineering. They need to withstand extremely harsh working conditions, including torque, pressure, wear, impact during high-intensity drilling, as well as corrosive media (such as hydrogen sulfide, carbon dioxide) and high temperatures that may exist in the underground environment. Therefore, geological seamless steel pipes have very strict requirements in material selection, manufacturing process and quality control. Nansteel Manufacturing Co., Ltd has carefully summarized the types, applications, standards and other related contents of geological seamless steel pipes.
Main types and applications of seamless steel pipes for geological use
Geological seamless steel pipes can be divided into the following categories according to their specific uses in geological engineering:
1. Geological drilling steel pipe
Uses: Mainly used in solid mineral and hydrogeological exploration, coalbed methane mining, trenchless horizontal directional drilling, etc. It directly participates in the drilling process, connects the drill bit, transmits torque and axial pressure, and transports flushing fluid.
Features: It is required to have high strength, high toughness, good wear resistance, fatigue resistance and excellent connection performance, usually with inside and outside thickened or inside and outside flat joint design.
Common materials: DZ40, DZ50, DZ60, DZ70, DZ80 and other grades, these are alloy steels specially designed for geological drilling. The higher the number, the higher the strength grade.
2. Oil drilling steel pipe
Although commonly associated with "petroleum", they also fall into the broader category of "geology" because oil and gas drilling is an important part of geotechnical engineering.
Types:
Drill Pipe: Connects to the drill bit, transmits drilling torque and axial force, and transports drilling fluid. It requires high strength, high toughness and fatigue resistance. Common brands include E75, X95, G105, and S135.
Tubing: Used to extract oil and natural gas from oil and gas wells. It is required to have good tensile strength and corrosion resistance. Common grades include J55, N80, L80, and P110.
Casing: Fixes the well wall, isolates different strata, prevents stratum collapse and fluid cross-layer, and requires good compression strength and tensile strength. Common grades include J55, K55, N80, L80, P110, Q125, etc.
Features: Strict requirements are placed on the material's strength, toughness, yield strength, collapse resistance, and resistance to hydrogen sulfide stress corrosion cracking (SSC) and carbon dioxide corrosion (CO2 corrosion).
Seamless steel pipe for mining
Application: Used for gas extraction, grouting, drainage, ventilation, etc. in coal mines.
Features: Pressure bearing capacity and corrosion resistance, some pipes may need to be wear resistant.
Common materials: carbon steel materials such as Q235, Q345, or anti-corrosion treatment as needed.
Seamless steel pipe for engineering piles
Uses: As foundation piles in foundation engineering, bearing the superstructure.
Features: It is required to have good strength, toughness, weldability and be able to resist corrosion in underground environments.
Common materials: Q235, Q345 and other structural steels.
Special requirements for seamless steel pipes for geological purposes
High strength and toughness: to cope with the impact, vibration and torque during complex drilling processes.
Wear resistance: Friction with rocks or soil during drilling.
Fatigue resistance: withstand long-term reciprocating stress.
Corrosion resistance: To deal with corrosive media such as groundwater, hydrogen sulfide, and carbon dioxide, a higher level of resistance to sulfide stress corrosion cracking (SSC) and carbon dioxide corrosion (CO2 corrosion) is required for "sweet gas wells" and "sour gas wells" with high hydrogen sulfide content.
Dimensional accuracy and straightness: ensure smooth assembly and lowering of drilling tools into the wellbore.
Joint connection reliability: drill pipe, tubing, and casing all need to be connected through threaded joints, which require high joint strength and good sealing.
Common geological seamless steel pipe standards
API Spec 5DP: Specification for drill pipes in the petroleum and natural gas industry.
API Spec 5CT: Specification for casing and tubing in the petroleum and natural gas industry.
GB/T 9808: Steel pipes for geological drilling.
YB/T 5212: Pipes for geological core drilling.
MT/T 1082: Seamless steel pipes for underground gas extraction in coal mines.
Geological seamless steel pipes are key materials that support the safe and efficient operation of geological exploration, oil and gas development, and underground engineering. Their high quality and high performance are the fundamental guarantee for the success of the project.
Read more: Corrosion Resistance of Galvanized Seamless Steel Pipe
Main types and applications of seamless steel pipes for geological use
Geological seamless steel pipes can be divided into the following categories according to their specific uses in geological engineering:
1. Geological drilling steel pipe
Uses: Mainly used in solid mineral and hydrogeological exploration, coalbed methane mining, trenchless horizontal directional drilling, etc. It directly participates in the drilling process, connects the drill bit, transmits torque and axial pressure, and transports flushing fluid.
Features: It is required to have high strength, high toughness, good wear resistance, fatigue resistance and excellent connection performance, usually with inside and outside thickened or inside and outside flat joint design.
Common materials: DZ40, DZ50, DZ60, DZ70, DZ80 and other grades, these are alloy steels specially designed for geological drilling. The higher the number, the higher the strength grade.
2. Oil drilling steel pipe
Although commonly associated with "petroleum", they also fall into the broader category of "geology" because oil and gas drilling is an important part of geotechnical engineering.
Types:
Drill Pipe: Connects to the drill bit, transmits drilling torque and axial force, and transports drilling fluid. It requires high strength, high toughness and fatigue resistance. Common brands include E75, X95, G105, and S135.
Tubing: Used to extract oil and natural gas from oil and gas wells. It is required to have good tensile strength and corrosion resistance. Common grades include J55, N80, L80, and P110.
Casing: Fixes the well wall, isolates different strata, prevents stratum collapse and fluid cross-layer, and requires good compression strength and tensile strength. Common grades include J55, K55, N80, L80, P110, Q125, etc.
Features: Strict requirements are placed on the material's strength, toughness, yield strength, collapse resistance, and resistance to hydrogen sulfide stress corrosion cracking (SSC) and carbon dioxide corrosion (CO2 corrosion).
Seamless steel pipe for mining
Application: Used for gas extraction, grouting, drainage, ventilation, etc. in coal mines.
Features: Pressure bearing capacity and corrosion resistance, some pipes may need to be wear resistant.
Common materials: carbon steel materials such as Q235, Q345, or anti-corrosion treatment as needed.
Seamless steel pipe for engineering piles
Uses: As foundation piles in foundation engineering, bearing the superstructure.
Features: It is required to have good strength, toughness, weldability and be able to resist corrosion in underground environments.
Common materials: Q235, Q345 and other structural steels.
Special requirements for seamless steel pipes for geological purposes
High strength and toughness: to cope with the impact, vibration and torque during complex drilling processes.
Wear resistance: Friction with rocks or soil during drilling.
Fatigue resistance: withstand long-term reciprocating stress.
Corrosion resistance: To deal with corrosive media such as groundwater, hydrogen sulfide, and carbon dioxide, a higher level of resistance to sulfide stress corrosion cracking (SSC) and carbon dioxide corrosion (CO2 corrosion) is required for "sweet gas wells" and "sour gas wells" with high hydrogen sulfide content.
Dimensional accuracy and straightness: ensure smooth assembly and lowering of drilling tools into the wellbore.
Joint connection reliability: drill pipe, tubing, and casing all need to be connected through threaded joints, which require high joint strength and good sealing.
Common geological seamless steel pipe standards
API Spec 5DP: Specification for drill pipes in the petroleum and natural gas industry.
API Spec 5CT: Specification for casing and tubing in the petroleum and natural gas industry.
GB/T 9808: Steel pipes for geological drilling.
YB/T 5212: Pipes for geological core drilling.
MT/T 1082: Seamless steel pipes for underground gas extraction in coal mines.
Geological seamless steel pipes are key materials that support the safe and efficient operation of geological exploration, oil and gas development, and underground engineering. Their high quality and high performance are the fundamental guarantee for the success of the project.
Read more: Corrosion Resistance of Galvanized Seamless Steel Pipe
