Research On South Xing PuI3 Layer Influence Factors Of The Occasion To Changing The Polymer Flooding With Following Water Flooding

Xing shugang's structure is a three-grade structure in southern Changyuan of Daqing and the pure oil in Xing twelve area is located in southern Xingshugang oilfield.Since from 1971 put into development,it has experienced some multiple development ways such as the water flooding,polymer flooding and chemical flooding.Most of the current regions have entered into the high water-cut stage,the difficulty of further tapping the potential is increasing.The way of changing polymer flooding with subsequent water flooding can tap the local residual oil effectively,right occasion is essential.Study on influence factors of the occasion to changing the polymer flooding with following water flooding can provide technical support for remaining oil production with water flooding after polymer flooding.It has a long term economic benefit and social benefit,as well as the vital significance.In this paper,It based on the actual situation of the block and made use of the Eclipse software to simulate the history of water flooding and the CMG software STARS to history matching for polymer flooding stage.Analysing geological factors(permeability ratio,high permeability ratio,the number of connectivity direction,the degree of control)and the development factors(polymer dosage,injection rate,injection concentration,water cut before polymer flooding,oil saturation before polymer flooding,well spacing,subsequent water flooding water-cut,subsequent water flooding oil saturation)to the effects on recovery rate,we got the main factors to effect the occasion to changing the polymer flooding with following water flooding.We made the predictions of development effect in different water cut levels,different polymer dosage,different oil saturation under the condition of subsequent water flooding.Taking all factors on the development effect and economic benefit into consideration,we got the best economic boundaries in their cases.Meanwhile we studied the occasion of well group to changing with subsequent water flooding.Results show that:to the five point well network(four inject and one produce),when four wells reach water cut limit with the subsequent water flooding,the development effect and economic benefit is the best.