Changyou was founded in 2010, specialized in design, manufacturing, surface test and sales of oil drilling equipment, downhole well testing equipment(drill stem test/DST tools,mechanical&pressure control) and exploration equipment. Except that, also offer the R&D service to the clients who gets special requirements . Covering an area of 3,000 square meters, has about 50 experienced workers and 30 professional technicians. With more than 10 years working experience in designing and manufacturing downhole well testing tools. Chanyou has rich design experience, site experience, strong technological innovation and production capabilities.Fist tools products include(full bore/opening type DST tools): super safety valve(SSV), slip joint, RD(S) circulating valve, drain valve, circulating valve(single&multi), tester valve(normal&lock/hold open), gauge carrier, jar, sampler, safety joint, packers, absorber(horizontal&vertical) and so on. As a professional equipments manufacturer and producer, Changyou also possesses a number of patents with independent intellectual property, which provide a powerful technical support for our clients.Always depends on scientific and technological innovation for a better development, with advanced processing equipment, comprehensive test means, products of good quality, and a sound after-sales service provides our costumer with high-quality products. And we always adhere to the principal "Technology decide market" to provide a better service for our customer. Looking into the future, Changyou will always follow the corporate culture "Self break-through, Striving for excellence, Never satisfied" and the "Zero defect" business philosophy in the whole production process. Meanwhile, always keep pace with the developing new technology to provide a better service and product to our costumer , and make unremitting efforts to the development of China petroleum manufacturing industry.