Novel Profile Control Treatment Using Pore-Scale Polymer Elastic Microspheres

Abstract

In order to solve the deep profile control problem and improve oil recovery of the oilfield, a novel profile control agent pore-scale polymer elastic microspheres (PSPEMs) was synthesized. The swelling property of PSPEMs in aqueous solution was analyzed. Core flow test and double-tube sand pack models were used for studying profile control and flooding performance of PSPEMs in oil formation. The results show that PSPEMs have good swelling property in aqueous solution with high salinity, high temperature and high pressure. Fig 5 and Fig 6 show that PSPEMs are better than polyacrylamide polymer on profile control. Table 1 indicates PSPEMs can improve water injection profile of heterogeneous formation effectively and plug the high permeable layer first. The higher the concentration of PSPEMs, the shorter the time it spends to realize profile control. The results also confirm that use proper concentration of PSPEMs, the profile control efficiency can increase enormously.

New Method Based on CO2-Switchable Wormlike Micelles for Controlling CO2 Breakthrough in a Tight Fractured Oil Reservoir

“…The pressure changing was detected by the sensor. The permeability ( k wb , given in units of μm 2 ) and the plugging rate (η, expressed in units of %) of the sand pack model after the plugging process were calculated using the following equations: , where Δ P is the injection pressure difference (given in units of 10 –1 MPa), Q is the injection rate (given in units of mL/s), μ is the viscosity of brine water (given in units of mPa s), A and L are the sectional area and length of the sand pack model, respectively (expressed in units of cm 2 and cm, respectively), and k wa is the initial permeability of the sand pack model (given in units of μm 2 ). The main equipment is shown in Figure .…”

“…The pressure changing was detected by the sensor. The permeability (k wb , given in units of μm 2 ) and the plugging rate (η, expressed in units of %) of the sand pack model after the plugging process were calculated using the following equations: 38,39…”

Preparation and performance of fluorescent polyacrylamide microspheres as a profile control and tracer agent

“…The differential pressures (DP, given in units of MPa) were measured during the whole injection process. The permeability of the sand pack in the displacement process (k, given in units of lm 2 ), and the plugging rate (g, expressed in units of %) were calculated using the following equations (Qin and Li 2006;Lei 2011…”

Enhanced Oil Recovery Using Micron-Size Polyacrylamide Elastic Microspheres: Underlying Mechanisms and Displacement Experiments

“…Many chemical agents have been applied to control profile and enhance oil recovery of heterogeneous reservoirs. There are many cases reported that bulk gel, weak gel, colloidal dispersion gel (CDG), and precross-linked particle gel (PPG) can control profile and enhance oil recovery of heterogeneous reservoirs effectively and are widely used in oilfield development. − In the early 21st century, a smart profile control and oil displacement agent with elasticity called “micron-size polyacrylamide microspheres (MPEMs)” was developed to control profile in oil reservoirs with high temperature and high salinity . The MPEMs are size- and strength-controlled, environmentally friendly, and not sensitive to reservoir minerals and formation water salinity.…”

“…5−15 In the early 21st century, a smart profile control and oil displacement agent with elasticity called "micron-size polyacrylamide microspheres (MPEMs)" was developed to control profile in oil reservoirs with high temperature and high salinity. 16 The MPEMs are size-and strength-controlled, environmentally friendly, and not sensitive to reservoir minerals and formation water salinity. They can deform depending on their elasticity and pass through the pore-throats under a large pressure difference to achieve a dynamic process of profile control and oil displacement.…”