At present, the main series of oil casing special buckle designed and developed in the world are four categories, respectively: VM series, Hydrir series, Hunting series, Tenaris series.
Special buckle features
Although the design of special fasteners for oil casing varies from country to country and company to company, the basic form is basically the same, mainly to improve the connection strength and sealing performance of the pipe string.
On the other hand, most oil casing special connections are divided into three parts: the connection thread part, the anti-torque table shoulder and the sealing surface part.
Most use API trapezoidal threads to improve the interchangeability of the thread portion.
Advantages of special buckle:
At the beginning of the use of oil well pipe, the special buckle is designed for different oil fields, different blocks and different well conditions, which has a strong personalized color. However, as well conditions become more complex, the operating conditions of pipelines become more stringent. Through the comparison, screening and practical tests of various foreign special fasteners, more than 10 typical products have been gradually formed, which can basically meet the special needs of current oil fields. Although various special buckle products can meet the needs of drilling and production under different simultaneous conditions, they all have the following advantages in common:
- The connection strength of the joint can match the strength of the pipe body, and even some are higher than the joint strength of the pipe body for deep Wells and ultra-deep Wells;
- With good sealing performance, it is suitable for high-pressure gas Wells, oil Wells and thermal production Wells
- Strong bending resistance, suitable for matching Wells, large displacement Wells and horizontal Wells;
- It is easy to fix, can be quickly fastened, and is not easy to drill in harsh environments such as deserts and oceans;
- Good anti-viscosity, can be removed repeatedly without damaging the thread;
- Strong torque resistance;
- Good corrosion resistance
