In brief this paper provides the new theory basis and the method for the research well wellheaddevice operating performance and the development high performance.
总之本文为研究采油井口装置工作性能，开发高性能的采油井口装置提供了新的理论依据和方法。
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Balance weight set free fall emergency braking device, which can realize auto control load loss protection, when the wellhead end accidental loss of load, balance weight free fall.
The casing hanger provides a means of ensuring that the string is correctly located and generally incorporates a sealing device or system to isolate the casing annulus from upper wellhead components.