G43断块油藏整体压裂技术研究与应用

G43区块主力产层为中孔中渗储层,地层饱和压力低,弹性采收率低;岩石塑性较强,造成支撑剂嵌入,前期压裂效果差。为提高压裂开发效果,进行了整体压裂技术研究。通过原油性质测试表明,区块原油胶质沥青质较重,在前置液前加降黏液以避免原油乳化;岩石力学试验表明,区块岩石易发生支撑剂嵌入,且储层为中孔、中低渗储层,压裂设计应以提高裂缝导流能力为主,具体措施包括通过单剂优选和整体性能测试,优选出适合G43区块的压裂液体系,该体系具有携砂性能好、低摩阻、低残渣的特点,可减少压裂液对地层及支撑裂缝的伤害;通过支撑剂导流能力试验,结合整体压裂裂缝参数优化,采用大粒径陶粒或组合陶粒压裂技术提高支撑裂缝导流能力。3口井的现场实施表明,G43断块整体压裂各项技术措施针性强,压后增产效果显著,推动了G43区块压裂开发的有效实施。

Research and application of systematic fracturing technology of oil reservoir in Block G43

The main producing formation of Block G43 is medium porosity and permeability reservoir,and the saturated pressure and elastic recovery ratio are low.Strong plasticity makes the effects of fracturing become worse.In order to enhance the fracturing effects,the research on systematic fracturing technology was carried out.The crude oil test shows that the asphaltene content is high,so the viscosity breaking fluid is added in the prepad fluid period.The rock mechanics test shows that the embedding extent is strong and the reservoir has medium porosity and permeability,so improving fracture conductivity is the main design idea.The detailed measures include： through additives optimizing and fluid performance test,the fracturing fluid system is optimized,which has good sand-carrying performance,low friction and residue,so the damage of fracturing fluid to formation and propped fracture are low;based on the conductivity test and combined with the parameters optimization of systematic fracturing,big diameter or mixed diameter proppant technique is proposed to improve the propping fractures conductivity.The field applications of 3 wells show that the effect of fracturing is remarkable,which promotes the application of systematic fracturing in Block G43.