Molecular Film Flooding Analysis On The Core From5-164Rinsing Inspection Well In Shanshan Oilfield

Molecular film flooding is a new type of enhanced oil recovery technology, some old oifields have carried out preliminary tests,and got significant increasing yield. Shanshan oil-field based on productive situation that the oil field has entered high water cut, determined the technical route "reconstructing well network, changing flooding medium" to solve practical problem of large amplitude decline, high water cut in production. In this paper, we’re aim at the route of "changing flooding medium", put forward a molecular films flooding technology. Do laboratory molecular film flooding analysis the core from5-164rinsing inspection well, to check molecular films flooding suit for Shanshan oilfield.The first,second,third chapter mainly introduce the basic situation of Shanshan oil field and the present research situation of molecular firm flooding.The fourth chapter introduce molecular film of static adsorption, oil-water distribution coefficient from the molecular film flooding mechanism.And the fifth chapter study molecular film effect on wettability changing. The sixth chapter draws the core oil-water relative permeability curve, compares the difference of water flooding and molecular film flooding oil-water relative permeability curve. The seventh chapter, the eighth chapter by doing series flow experiments, evaluate molecular film oil displacement efficiency, and optimize the injection parameters of molecular film flooding.Determine different concentrations solutions of YMD, MD-1, MD-2molecular film agents’static adsorption capacities on core silty sand and the distribution coefficient in water and oil:The adsorption capacities on core silty sand increased with concentration of the molecular films, when MD-l’s concentration is1600mg/L, it has saturated adsorption, the value is11.74mg/g; MD-2’s concentration is1800ppm, it has saturated adsorption, the value is14.73mg/g; YMD when the concentration is1600mg/L, the saturated adsorption quantity12.77mg/g; The distribution coefficient of molecular film in oil and water phases:with the increase of concentration, distribution coefficient decreasing,"molecular film dissolution" in the oil phase is minimal.Measured different solutions change wettability on glass by using measure contact angle method. The initial state glass is strong hydrophilic which surface contact angle is less than10°,immersioned by kerosene,salt water and deionized water soaking, the contact angle increased in different degrees,but all are less than9O°,still as a hydrophilic surface;immersioned by MD-2solution,the contact angle greater than90°, the wettability become hydrophobic. On this basis, studied the MD-2solution change to the wettability of core slice surface:the core slice’s contact Angle is about25°without immersing by MD-2solution, while immersed contact Angle increased to90°,thus MD-2can change core’s wettability, weaken its hydrophilic.Using steady state method measured water flooding and molecular film flooding change to the relative permeability on4different permeability cores, and drawing relative permeability curve:with the decrease of core permeability, bound water saturation and residual oil saturation increased, water flooding efficiency reduced.Focus on53cores, contrasted the relative permeability curves change of oil-water/molecular film flooding:compared with water flooding, molecular film flooding can decrease residual oil saturation3.8%, increases oil phase permeability, increase oil recovery6.82%.Do series of molecular deposition film flooding.Evaluated oil displacement efficiency of three kinds of molecular film agents MD-1, MD-2and YMD by single core experiments:on the conditions that same films concentration and similar core physical parameters, compared with water flooding, MD-2can improve recovery5.59%, YMD is3.95%, MD-1is3.89%.Using parallel core experiments to simulate molecular films effect on recovery in interlayer heterogeneous reservoir:After water flooding, profile control and water flooding, then molecular film flooding, MD-2flooding can increase the low permeability core recovery8.4%, high permeability core recovery4.4%. MD film flooding can improve the micro wash oil efficiency.Investigated intralayer heterogeneity effect on MD-2molecular film flooding recovery in use of indoor2-dimensional model:in plane homogeneous model A,the early water flooding recovery was46.13%,when injected the molecular film,the recovery increased by4.67%,subsequent water flooding improved recovery3.38%,the total recovery54.18%.In plane heterogeneity model B, the early water flooding recovery was35.82%, early molecular film flooding recovery just increased3.41%.After injecting weak gel to control profile, the recovery of low permeability increased by10.37%. Subsequent water flooding and molecular film flooding, continue to draw on low permeability zone, the total recovery increased7.83%.Optimized MD-2molecular film flooding injection parameters:evaluated different concentration MD-2solutions from200ppm to2000ppm effect on improve recovery, the recovery increased by Molecular film concentration, When MD-2concentrations is greater than1800mg/L, the recovery remain basically unchanged, so the optimal concentration is1800mg/L.Evaluated continuous injection, high concentration of small slug, low concentration of large slug and stepped concentration slug injection effects on recovery, The experimental results show that the maximum increased recovery is9.37%by low concentration of large slug injection, therefore the implementation of molecular film flooding to use low concentration of large slug injection.Compared the recovery of transfused to MD-2molecular film flooding at different injection time, when the water cut is60%,70%,80%,90%and100%in produced liquid, transfused to injected MD-2molecular film, the results showed that transfered molecular film earlier, recovery higher. Yet we need maximum total recovery in field production, thus when water cut is80%we transfered to molecular film flooding. It’s the optimum injection time. Summary:the optimum injection concentration of MD-2is1800mg/L, the optimum injection at water cut80%transfer molecular film flooding, injection mode for low concentration of large slug.