Current situation and development trend of cementing technology in China

Current situation and development trend of cementing technology in China

（1） Oil well cement and additives

Since 1990, China has promulgated a new standard for "oil well cement", which has eliminated the old cement standards of 75, 95 and 120 ℃. The transition from oil well cement to API standard has been completed and the quality of oil well cement has been improved. In order to solve the problem of early strength of low temperature cement stone, Daqing Oilfield studied and applied high alumina cement with relevant cement manufacturers and achieved good results. The comparative research and application of cementing basic cement at home and abroad are mainly manifested in insufficient research investment, few types of basic cement and less application.

In the research of oil well cement additives, China has experienced the process of introduction, imitation, self-study and matching. So far, more than 100 kinds of cement slurry additives have been formed, which basically meet the needs of domestic oilfield development. The performance of dispersant, low temperature anti gas channeling agent and conventional fluid loss additive has approached or reached the advanced level abroad. There are few kinds of admixtures with high temperature and salt resistance in China, and their performances are unstable; there are few researches on siliceous materials to reduce or prevent high temperature strength degradation, and their quality is unstable; Chinese oil well cement admixtures generally act independently and have poor compatibility; Due to the investment, the average consumption of oil well cement in China is 1 ton, and the consumption of additives is 0.057 tons and 0.17 tons abroad.

（2） Conventional cementing technology

China has perfected 14 cementing technologies for 8 kinds of reservoirs. Many special cementing technologies such as liner cementing, double stage cementing and horizontal well cementing have been widely used and gradually evolved into conventional cementing techniques. However, compared with foreign countries, there is still a big gap in ultra-low density cement slurry cementing, high density cement slurry cementing and ultra deep well high temperature cementing.

（3） MTC cementing technology

Since 1992, a lot of research and application of MTC cementing technology have been carried out in our country. We have mastered the activation, performance control and field operation technology of transforming drilling fluid into cement slurry, and hundreds of wells have been applied in the field. In the future, it is necessary to further strengthen the research on the hydration mechanism of MTC and the high temperature, high pressure and long-term mechanical properties of MTC solidified products, simplify the field construction technology and broaden its application scope.

（4） Development of cementing tools

Liner hanger, double-stage cementing device, casing centralizer, casing packer and conventional tool accessories basically meet the field cementing technical requirements. The quality and reliability of cementing tools are close to the level of foreign products. Compared with foreign countries, China has a big gap in terms of rotatable liner hanger, liner hanger with packer, multi-stage cementing tools and special cementing accessories for extended reach wells.

（5） Computer simulation and design software for cementing

The advanced computer simulation and design software for cementing has been developed by Southwest Petroleum Institute and other units in China. Every oilfield in China has its own cementing design software. But the advanced, scientific and functional aspects of software need to be improved. The real-time monitoring and operation evaluation system is not widely used.