과거에는 석유를 추출할 때 간단한 기계 도구를 사용하여 우물을 파고 석유 작업자가 우물 가장자리에 서서 석유 추출 및 파이프라인 운송을 수행했기 때문에 안전과 효율성에 큰 문제가 발생했습니다. 주요 측면은 다음과 같습니다: 첫째, 하층의 물과 토양이 기름과 쉽게 혼동되어 추출된 기름의 순도를 보장할 수 없습니다. 둘째, 유전 내부에 지지대가 없기 때문에 작업자의 생명과 장비 작동에 큰 안전 위험이 있습니다. 이 경우 많은 설계자가 석유 산업을위한 전체 파이프 라인 시스템 세트를 개혁하는 것을 목표로하여 오일 케이싱이 탄생했습니다.

1, 그것은 석유 케이싱이 너무 많은 장점을 가지고, 점점 더 많은 석유 광산 회사가 가공으로이 재료 세트, 석유를 추출하는 데 필요한 소품이 될 것입니다, 조립이 상대적으로 쉽기 때문에 점점 더 많은 제조업체가 단일 정보의 생산으로 이동하기로 선택한 다음 제조업체가 간단한 조립을 수행하기 위해 구입합니다.

2, 오일 케이싱은 석유 추출, 운송, 고체 보증을위한 파이프 라인 시스템으로, 주로 안전한 작동을 위해 지하에서 석유 작업자 였고 그런 종류의 작업 환경에 처해 있다면 오일 케이싱을 사용한 후 하늘이 무너질까봐 걱정하지 않는 것처럼 전체 작업 장소가 견고해진다는 것을 이해할 것입니다. 이 경우 집중적이고 신중한 작업 프로세스를 달성하는 것이 더 쉽습니다. 오일 케이싱이 탄생 한 이래 수많은 석유 노동자들은 산업이 더 이상 이전만큼 위험하지 않다고 느꼈습니다.

Surface casing
1、Used to seal the upper unstable loose, collapse-prone and leaky formations and water layers.
2、Installation of wellhead device to control well blowout.
3、Support part of the weight of technical casing and oil layer casing.

The depth of the surface casing down depends on the specific situation, usually a few dozen meters to a few hundred meters or deeper (30 to 1500m). The cement return height outside the tubing is usually returned to the surface. When drilling high-pressure gas wells, if the upper rock layer is loose and broken, the surface casing needs to be lowered to prevent the high-pressure gas from escaping the surface. If the surface casing needs to be deeper and the first drilling time is longer, a layer of conduit should be considered before placing the surface casing. Its function is to seal the surface, prevent the collapse of the wellhead and form a drilling fluid circulation channel for a long drilling period. The conduit is generally lowered to a depth of 20-30 meters, with the cement outside the conduit returned to the surface. The conduit is usually made of spiral or straight seam pipe.

Technical Casing
1、It is used to seal complex formations where drilling fluid is difficult to control, severe leakage layers, and oil, gas and water formations where the pressure difference is significant, etc., to prevent the well diameter from expanding.
2、In directional wells with large well slope, technical casing is lowered in the slope-making section to facilitate the safe drilling of directional wells.
3, for the installation of well control equipment, blowout prevention, leak prevention and suspension of the tail pipe to provide the conditions, the formation casing also has a protective role.

Technical casing does not have to be lowered, but can be controlled by using high quality drilling fluids, accelerating drilling speed, strengthening drilling and other measures to control the complexities of the well, and strive not to lower or less technical casing. The depth of the technical casing is determined by the complex formation to be sealed. The cement return height should reach more than 100 meters of the formation to be sealed, and for high-pressure gas wells, the cement is often returned to the surface in order to better prevent gas leakage.

Oil Formation Casing
It is used to seal off the target layer from other layers; to seal off oil, gas and water layers with different pressures, and to establish an oil and gas channel in the well to ensure long-term production.
The depth of the formation casing depends on the depth of the target formation and the completion method. For high pressure wells, the cement slurry should be returned to the ground to reinforce the casing and enhance the sealing of the casing wireline so that it can withstand the larger shut-in pressure.

Petroleum casing emerged not only for oil extraction but also as a pipeline for transporting raw materials. In order to strengthen the quality of petroleum casing, every link in the production process is particularly important, especially the temperature control during the period, which must be mastered in strict accordance with the regulations. Usually, the petroleum casing is quenched by sub-temperature quenching method instead of the ordinary quenching method, because the ordinary quenching method adopted will allow a large amount of residual stress inside the workpiece, thus expanding the brittleness, and the subsequent processing is not so convenient. The sub-temperature quenching is to prevent the brittleness of the oil casing from affecting the subsequent process. The main operation method is to first select the heating temperature for sub-temperature quenching, usually between 740-810°C, and the heating time is usually about 15 minutes. After quenching and then tempering, the heating time of tempering is fifty minutes, and the temperature should be selected to 630°C. Of course, each type of steel has its own heating temperature and time during heat treatment, and as long as the performance of the workpiece can be improved and enhanced, then the purpose of heat treatment will be achieved.

Heat treatment is the most important process in the processing of oil casing, the performance and quality of the finished product can meet most of the results of heat treatment, so the manufacturers of heat treatment process requirements are very strict, do not dare to have a trace of slack. Sometimes can also be quenched by means of low-temperature quenching, low-temperature quenching can effectively remove the residual stress of the oil casing, not only to reduce the degree of deformation of the workpiece after quenching, but also to process the oil casing into a more suitable raw material for the later process. Therefore, the current achievements of petroleum casing and heat treatment are inseparable. Since the heat treatment process, regardless of the impact toughness, destruction resistance or tensile strength of petroleum casing, there has been a great improvement.