Synthesis And Application Of Timing Reaction Cross-linking Agent And High Elastic Composite Particles For Depth Profile Control

The oilfield has already entered specially high water cut development phase,the water cut has reached more than80%. After a long time of exploiting,because of thick reservoirs and serious heterogeneity, water channeling has beenformed in oil layers, and large amount of injected water did inefficient orineffective circulation along the high permeability zone and large pores, thismeans a direct impact on the effectiveness and economic efficiency.Over the years, the depth profile control technology is always an importanttechnique of water control. Therefore, the study of low-cost and high-efficiencydepth profile control system for high water cut stage of oilfield is of importantsignificance.Generally speaking, the depth profile control system contains two categories,those are gel and particulate. Gels are mostly metal cross-linked polymers andresins. Controllability of metal cross-linked polymers’ gelling time and intensityare not good. Resins are high-cost and harmful to the environment. So, it isnecessary to develop retarded cross-linking gels and elastic composite particles.In this paper, we established two specific experimental programs after theresearch of literatures:(1) According to the mechanism of retarded crosslinking, we synthesizedmany different combinations of organic Cr complexation crosslinking agent,with the Cr3+was the central metal ion and acetic acid, lactic acid and humic acidwere ligands. By changing the proportion of polymers and cross-linking agents,we study the systems’ viscosity and gelling time in rinsing and sewage. Theresults showed that the gelling time of the system is controllable around10~12days when the ratio of polymer and cross-linking agent is60:1~80:1.(2) By a large number of experiments, we synthesized35composite particleproducts, with the first monomer was acrylamide, the second was hydrophobicmonomer, and inorganic additives were bentonite and diatomite. Then we tested the density, expansion and via-hole strength of the particle products. After15days’ expansion detection, there were three kinds of composite elastic granularproducts whose cross-hole pressure were greater than1.5MPa.