Study On The Law Of Water Drive In The Extra High Water Cut Stage Of GD Oilfield

After the oil field enters the extra high water cut stage,the comprehensive water cut of the oil field is high,and water cut of the most production wells is above 95% or even over 98%.It is difficult to distinguish the flooding conditions of different wells only by the water cut.Therefore,in the extra-high water cut stage studying the law of water drive will help to evaluate the development of oilfields and provide the necessary basis for the decision-making of water drive.Because the law of water drive is a complicated problem,it is divided into three parts for research: 1)identification of the plane diction of the water channel,2)determination of water drive breakthrough time 3)method of calculating water drive sweep volume.Due to in the ultra-high water cut stage most oil wells are flooding,it is hard to effectively distinguish the flooding degree of different wells.Although well testing can obtain interwell relationships,it affect normal production and can only obtain short-term relationships.Once the well network adjusted re-testing is required.Therefore,we researched interwell connectivity by production and injection data.According to this,the true flow direction and distribution ratio of the water injection water in the heterogeneous oil layer can be determined,and the position of the water channel can be effectively found.There are many studies on cross-well connectivity.Both static and dynamic methods have a variety of specific research methods that can be used to research.Based on the study of the plane connectivity relationship,the theoretical derivation about C-type water flooding curve was carried out.The qualitative analysis of the derivation results was carried out to obtain a method for distinguishing water flooding.Then quantitatively calculated of the theoretical derivation was used to improve the water drive sweep volume calculation method based on the C-type water drive curve,so that it can be used in a wider range.Over all,Method of calculating the connectivity between wells is established by using the production data in consideration of the invasion of external fluids,which can be used to determine the location of the channel.Based on the C-type water flooding curve,the discrimination of water drive breakthrough and the calculation method of water drive sweep volume are established.In order to facilitate the application of research results,software was designed to discriminate water drive breakthrough and calculate water drive sweep volume.Finally,the results of research were used to analyze and calculate the one well group in the west of 7th district of GD.The results show that these results can effectively analyze the main channel in the well group and calculate sweep volume.