Development And Application Of The Self-locking Fracturing Circulating Valve

Zhongyuan Oilfield currently use multistage packer fracturing without pulling string for major oiland gas well stimulation.As an important component of multistage packer string, fracturing circulatingvalve can be timely communicated with the oil sleeve, balance oil pressure differential, cleaning sand forfracturing the next layer. At the same time, the pressure releasing operation can eliminate closurepressure in pipe column by opening the valve cycle and reduce unblocking difficulty.Through the analysis of the fixed string multi-stage packer downhole working condition ofZhongyuan Oilfield.To determine the opening pressure with theoretical calculation and experimentmethods.Thecirculatingvalve’s opening pressure is too low, in the construction of oil, due to unbalancedimpulse effect and the misoperation reason to open, resulting in the construction schedule delay andrework problem. In order to solve this problem, in this paper, all kinds of domestic and foreigncirculating valve structure are deeply researched, developed a self-locking fracturing valve. In theprocess of design, by comparing the dynamic pressure feedback and spring pressure on the feedbacktwo kinds of plan, taking into account the cost control and site usability, decided to take the springpressure feedback system overall design circulating valve. The self-locking type circulating valve,spring, a sealing ring and other important parts, through the theoretical calculation of its size, materialdata preliminarily determined, through the ground experiments to verify and make correspondingadjustments; According to the geological features of Zhongyuan Oilfield, the corrosion experimentevaluation on main components circulating valve materials, ensure the reliability of the tool in theunderground working conditions.It has great significance and good economic benefits for the oilfieldfracturing through field application and solves the problems encountered in the construction.