Experimental Study On Deep Profile Control And Flooding With Micro-nano Microsphere In Pubei Oilfield

Pubei Oilfield locate in northern dome-shape structure of Putaohua Oilfield，the majorobject to develop is PI formation, the formation’s buried depth is800¹000m, the averageeffective formation porosity is21.3²4.4%, and effective permeability is103×10^-3μm². Atpresent, there are several problems, such as large interlamination contradictory, low controldegree of water flooding, and poor producing in thin/poor layer, when the oilfield developing.The key research object is how to solve these problems and further develop the remaining oilin Pubei Oilfield. As a new agent for deep profile control and displacement, the micro-nanomicrosphere has many good characters, it has small original size, good flowability, generallyswelling in flow process, and the multistage profile control and displacement in the formation.For this purpose, we propose the experimental study on deep profile control and displacementwith micro-nano microsphere in Pubei Oilfield. It could provide the theoretical foundationand technical support of advance high-efficient development in Pubei Oilfield.In this article, with the performance evaluation in laboratory, we analyze the dissolubility,swelling and rheological property of micro-nano microsphere in the injected water from Pubeioilfield the results show that the microsphere is good dispersion, and low viscosity, theswelling property of2000mg/L³000mg/L micro-nano microsphere is better. Considering thereservoir characteristic of Pubei oilfield, by use the artificial heterogeneous core, we study thedisplacement efficiency of microsphere effected by injection parameter such as injection rate,injection volume, microsphere concentration, injection pattern and slug size, then put forwardthe optimum injection parameter of the profile control and displacement by microsphere inPubei oilfield, the experiment of oil displacement conducted on artificial cores and naturalcores, it turns out that the effect of profile control and displacement by micro-nanomicrosphere is obvious, the oil recovery of aritificial core has been improved about17%, andthe nature cores are12%¹3%, on the base of water flooding, by injecting two slug ofmicrosphere, displacement efficiency could be much better. First conduct the profile controlbefore injecting the microsphere in reservoir with serious heterogeneity, the displacementefficiency will be improved, The study results have practical significance that realize thesustainable development in Pubei oilfield, the research achievement could provide the newmethod which will efficient improve the development effect in Pubei oilfield.