Microfluidic Dynamic Evaluation And Analysis Of Oil-water Flow Based On OpenCV

With most oilfields in China entering the high water cut stage,improving quality and efficiency has become an urgent task for most of them.Studying the dynamic model of microscopic oil-water flow in high water cut stage is beneficial to provide suggestions for EOR.And microfluidic technology is widely used in microscopic flow research.At present,although there are many visualization studies on microscopic oil-water displacement,few quantitative analysis methods are based on image visual features.The micro remaining oil occurrence state connects with the oil-water contact relationship,and there are few quantitative analysis methods to measure the contact angle based on image processing method.As for the microscopic oil-water dynamic flow model,there are few studies using microscopic data to present the overall model.In order to solve these problems,an automatic measurement method of microscopic three-phase contact angle based on digital image processing is proposed.The change of contact angle under various conditions is analyzed using this method witch is designed a software.Firstly,the adaptive threshold method is used to separate the stone,oil and water phases.The vertex of the contact angle is identified by the neighborhood domain detection method.The three-phase interface is fitted by the least square method.And a contact angle is calculated according to the three points’ coordinate position.So all contact angles are measured with all vertexes of contact angle.Manual measurements,wettability of microfluidic model and capillary pressure curves all verify the accuracy and effectiveness of this method.Secondly,the data characteristics of contact angle are analyzed in different displacement stages,different remaining oil types and different hole throat environments.We clarifies the dynamic change trend of the number,mean value and standard deviation of contact angles under various conditions,and further reveals the dynamic change of microscopic oil-water contact relationship in every stage of water cut.Considering the contact angle data and the distribution of hole and throat radius,a model for calculating the average capillary pressure curve is established in this paper so that the microscopic contact angle data is reflected in the overall dynamic model of microfluidic oil-water system.Combined with Brooks-Corey capillary pressure calculation model,the accuracy of the this model is verified.Finally,based on the Python,we designs a microfluidic dynamic analysis system with help of some open sources code module like Open CV,Sci Py,Num Py,etc.This software transforms the automatic measurement method of contact angle and its analysis process into simple and quick operation,which highlights the advantages of high efficiency,accuracy and unity in batch analysis of images.The software provides an application basis for quantitative identification and analysis of microscopic displacement experiments,and is beneficial to the oilfield researchers to improve their understanding of microscopic remaining oil distribution and microscopic oil-water contact relationship.