a In case of dispute, laboratory Rockwell C hardness testing shall be used as the referee method.
b No hardness limits are specified, but the maximum variation is restricted as a manufacturing control in accordance with 7.8 and 7.9.
c For through-wall hardness tests of grades L80 (all types), C90, T95 and C110, the requirements stated in HRC scale are for maximum mean hardness number.
API casing pipe is an essentialcomponent in the Oil and gasindustry. It plays a crucial role in the drilling and extraction of oil and gas from the earth’s subsurface. In this comprehensive guide, we will explore the various aspects of API casing pipe, including its definition, types, specifications, and applications.
To begin with, API casing pipe, also known as API Tubing, is a steel pipe used to line the walls of a wellbore during drilling operations. It is designed to withstand highpressure and provide structural integrity to the well. API casing pipe is manufactured in accordance with the American petroleum Institute (API) standards, which ensure its quality and performance.
Casing
There are several types of API casing pipe available in the market, each designed for specific applications. The most common types include seamless casing pipe and welded casing pipe. Seamless casing pipe is made from a solid piece of steel, while welded casing pipe is formed by welding steel plates together. Both types have their advantages and disadvantages, depending on the drilling conditions and requirements.
API casing pipe comes in various sizes and specifications to meet the diverse needs of the oil and gas industry. The size of the casing pipe is determined by its outer diameter (OD) and wall thickness. The most commonly used sizes range from 4 1/2 inches to 20 inches in diameter. The wall thickness can vary from standard to extra-heavy, depending on the well’s depth and pressure.
In addition to size, API casing pipe is classified into different grades based on its mechanical properties and chemicalcomposition. The grades range from H40 to Q125, with each grade having specific yield strength and tensile strength requirements. The selection of the appropriate grade depends on the well’s conditions, such as temperature, pressure, and corrosiveness.
API casing pipe is subjected to rigorous testing and inspection to ensure its quality and reliability. These tests include visual inspection, dimensional inspection, mechanical properties testing, and Non-destructive testing. The results of these tests determine whether the casing pipe meets the API standards and can withstand the demanding conditions of oil and gas operations.
The applications of API casing pipe are vast and varied. It is primarily used for drilling and completing oil and gas wells. The casing pipe is inserted into the wellbore and cemented in place to prevent the collapse of the well walls and the migration of fluids between different formations. It also provides a conduit for the extraction of oil and gas from the reservoir to the surface.
