Assessment of residual oil saturation with time-differentiated variable multiple material balance model

This study aims to improve the evaluation of residual oil saturation in water flooded zones based on the material balance model(MBM)with variable multiple for injected water.We investigated the change patterns of rock-electro parameters during waterflooding through the analysis of displacement tests.Our work differentiated the waterflooding into numerous displacement processes and accordingly propose an improved time-differentiated variable multiple MBM.The calculation results of the improved model are more consistent with the displacement experiment data of cores.Furthermore,the improved method was integrated into the comprehensive interpretation platform of offshore logging to analyze water flooded zones of a well in the A oilfield.As a result,the residual oil saturation calculated is in close agreement with the results of experiments on cores.Our results indicate that the time-differentiation and variable multiplier for injected water can effectively enhance the assessment accuracy of the residual oil saturation of water-flooded zones.

Experimental investigation of wettability alteration on residual oil saturation using nonionic surfactants: Capillary pressure measurement

Introducing the novel technique for enhancing oil recovery from available petroleum reservoirs is one of the important issues in future energy demands.Among of all operative factors,wettability may be the foremost parameter affecting residual oil saturation in all stage of oil recovery.Although wettability alteration is one of the methods which enhance oil recovery from the petroleum reservoir.Recently,the studies which focused on this subject were more than the past and many contributions have been made on this area.The main objective of the current study is experimentally investigation of the two nonionic surfactants effects on altering wettability of reservoir rocks.Purpose of this work is to change the wettability to preferentially the water-wet condition.Also reducing the residual oil saturation(Sor)is the other purpose of this work.The wettability alteration of reservoir rock is measured by two main quantitative methods namely contact angle and the USBM methods.Results of this study showed that surfactant flooding is more effective in oil-wet rocks to change their wettability and consequently reducing Sor to a low value.Cedar(Zizyphus Spina Christi)is low priced,absolutely natural,and abundantly accessible in the Middle East and Central Asia.Based on the results,this material can be used as a chemical surfactant in field for enhancing oil recovery.

Application of Tracer Model in the Remaining Oil Distribution of 95 Block Oilfields of Central Plains

With the development and utilization of oil and gas fields, oil mining become more and more difficult. The remaining re- serves of oil in the oil distribution is difficult to confirm, in order to understand and grasp the distribution of the remaining oil in the reser-voir, calculated using tracer concentration methods used mathematical models to calculate the residual oil saturation in the reservoir, from the theoretical analysis of tracer migration process, you can more accurately determine the distribution of the remaining oil, this method has good prospects for development.

The effect of type waves on vibroseismic implementation of changes properties of rock, oil viscosity, oil compound composition, and enhanced oil recovery

Based on the results of laboratory studies,the frequency of 35 Hz in longitudinal waves and 20 Hz in circular waves is the optimum frequency that can increase the maximum oil recovery.Coreflooding test results before the vibration effect can increase oil production by 51.96%and reduce the residual oil saturation by 59.03%The surprising results when the vibration effect was applied to the coreflooding test method with P wave types continuously succeeded in increasing oil production by 60.54%,inter-mittent P waves by 63.53%and circular waves by 64.76%,while also reducing Sor by 48.49%in continuous P waves,intermittent P waves at 44.81%and C waves at 43.3%,The P wave type vibrational method has an increase in oil gain by 16%,intemittently by 22%,Sor reduction by 18%and 24%,in circular wave oil gain increases by 25%,and Sor decreases by 27%from before the vibration effect given.Besides vibration can change the physical properties of rocks,among others;permeability has increased by 7%using P waves continuously,intermittently by 31%and C waves by 4%;porosity of 5.88%with P waves contin-uously,intermittently of 6.46%and circular waves of 4.63%;grain size before vibration of 45.16 um after vibration using continuous P waves of 42.01μum,intermittently of 4798μum,and circular of 50.46μum;changes in oil composition to contain more alkanes,and lack of aromatic compounds;oil viscosity increased by 3%with continuous P waves,intermittent of 5%,and circular 61%.The new point from this paper is analyzing the vibroseismic effect by using SEM images in terms of the watershed segmentation of the Rabbani algorithm compared to lab results,which have an error rate of under 2%,and a review of oil composition by the GC-MS method.