Research On Slotted Screen And Its Sand Control Technology

Sand production is one of the important tools that bother loose sand oil reservoir exploitation. Sand control technology and tool don't adapt serious sand production in middle and later stage of oilfield development and powdery sand production. Problems such as high sand control cost,short service life,low recovery ratio emerge. How to prevent and control sand production effectively is the hotspot that is being investigated all over the world. Deep investigation has been done to the most popular sand control tool—sand screen and its sand control technology. Creative achievements have been gotten.Aiming at problem that parallel-sided slots are easily blocked and openings of feathered slots are easily eroded and enlarged, which have influence on sand control effect and duration and so on, new compound slot configuration screen has been developed with lessons of hydrodynamics and mechanical sand control theory and research achievements.With the reference of fluid dynamics simulation software, flow resistance of parallel-sided slot,feathered slot and new slot has been analyzed in different environment. Corresponding law has been summarized. New slot configuration has been optimized. The new slot has advantages of low fluid resistance and high anti-corrosion. This kind of sand screens have been promoted in Shengli,Zhongyuan oil fields and get favorable results.Anti-corrosion of slot surface has much influence on sand control duration and service life of screens. Anti-corrosion of slots is mainly estimated with reference of corrosion theory of tubings and casings. Because physical and chemical property of slot surface has changed, its estimation result usually has deflection. Referring to this, anti-corrosion experimental research has been carried out. Corresponding relation has been summarized. Measurements to improve anti-corrosion of slot surface have been given.Influence of oil velocity,sand diameter,sand concentration,attack angle on erosion of slotted screen has been experimentally researched. Corresponding relation has been summarized. Measurements to improve anti-erosion have been given.Referring to fact that moderate production sand control technology needs periodical sand washing in well casing, prediction model of sand washing cycle is established according to multiphase flow theory. Corresponding software is programmed to calculate sand washing cycle and simulate sand production in VB language.