Slotted casing is an important completion key equipment in oil drilling operations. It is often used for early oil completion and sand control in oil production. Due to the good sand control performance, convenient construction and low cost of grooved casing, the demand for grooved casing in oil fields has increased rapidly. However, the extensive damage to slotted casing in oil fields not only disrupted the normal production plan, but also destroyed the normal injection and production well network system, causing huge losses and waste to the project. At present, many experts have conducted a lot of research work on how to prevent damage to grooved casing and have achieved many results. However, most of the research on grooved casing focuses on two aspects, namely, research on the processing technology of grooved casing and development of grooved casing. Research on sand control technology of grooved casing. Research on the strength of grooved casing is still in its infancy.
There are a certain number of abandoned oil wells in various oil fields in China, and sidetracking technology can activate these dead wells (re-produce oil), and the completion of sidetracking wells can also easily use slotted casing. Due to the superiority of slotted casing in horizontal wells and sidetrack well completions, slotted casing has received widespread attention in drilling and production in various oil fields. At the same time, each oil field has also increased research and development on the sand control technology of slotted casing. Application, and has made great progress, such as Dagang, Shengli and other oil fields have done a lot of work in this area and achieved good results. In short, the emergence of slotted casing has provided material conditions for the development of horizontal wells and sidetracking wells and oil production in high sand reservoirs.
Slotted casing technology refers to the use of advanced engineering equipment and efficient screen systems to accurately screen and slit oil wells to achieve high efficiency in oil-water separation in the reservoir. Through this technology, oil exploration companies can more accurately control the oil-producing and non-oil-producing layers in the reservoir, avoiding oil-water mixing and impurity pollution, thereby effectively improving oil production efficiency and oil field development and utilization. In practical applications, slotted casing technology not only plays an important role in conventional oil field production, but also shows unique advantages in the development of difficult-to-produce oil reservoirs. Through precise control and screening of wellbores, slotted casing technology can effectively improve the recovery rate of difficult-to-recover oil reservoirs, reduce the difficulty and cost of extraction, and bring considerable economic and social benefits to oil companies. In addition to improving oil recovery efficiency, slotted casing technology also plays a positive role in environmental protection. By reducing the mixing of oil and water and the emission of pollutants, this technology helps improve the environmental impact during oil field extraction, protect the ecological environment, and achieve the sustainable development goals of the oil industry.
Design of petroleum grooved casing
The size and shape of the slot width have a very important impact on the mechanical properties and sand prevention effect of the slotted casing. Designers design the relevant parameters of the slotted casing based on the geological conditions such as the viscosity of the crude oil, the particle size of the sand, and the production requirements after the oil well is put into production, including the design of the slot structure and the design of the slot layout.
The design of the seams of slotted casing must not only consider geological conditions and production requirements, but also must meet strength and stability conditions to ensure the operation safety and service life of slotted casing. For example, the longer the slot length and the number of slots in the slotted pipe are, the larger the flow area will be and the higher the output will be. However, at this time, the strength of the slotted casing will be reduced accordingly, the life span will also be reduced, and the chance of an accident will also be reduced. increase, so the pros and cons must be weighed during design to achieve the best effect.
Processing method of slotted casing
Whether a designed slotted casing can be formed into a product depends on the equipment capabilities and manufacturing process for manufacturing the slotted casing. In addition to conventional mechanical processing, there are also some special processes or combination processes. From the relevant patent documents and information materials, we can see the current processing status of slotted casing at home and abroad. At the same time, the problems existing in several manufacturing methods are also analyzed.
Slotted casing is a method of cutting multiple longitudinal or spiral straight gaps of certain specifications on oil casing and tubing or oil pipes in various ways. The gaps are cut using special ultra-thin cutting sheets or laser. The slotted casing has good sand-proof performance and no clogging, which can improve the quality of oil production. At the same time, the slotted casing also overcomes the phenomenon of "tangled threads" caused by collision, extrusion and friction with the well wall or casing when running down the well, improving the quality of oil production. Improve completion quality and sand control effect. Its appearance has attracted great attention from oilfield users. More than 90% of similar well completion methods in foreign countries use oil grooved casing. Therefore, grooved casing is the preferred supporting special pipe for current special oil production processes. Since horizontal wells can significantly increase oil production, horizontal well technology has developed rapidly in various countries in recent years, and the number of drilling wells has increased at an alarming rate.