The Research Of Well Cementing Flushing Spacer Liquid For Oil Base Drilling Fluid In The Deep And Ultra Deep Wells

With the development of high temperature wells,deep wells and some complex wells in the oil industry,oil based mud has been widely used.This is because of oil based mud plays a great role in drilling,improving drilling speed and dealing with complex underground conditions.However,The Oil based drilling fluid will remain in the first and second interfaces of the annulus to form oil slurry and oil film in the cementing construction,which will reduce the flushing effect of the spacer liquid and cause the cementing environment of the annular cement ring to be affected.In order to scour oil based mud mixture attached to the first and second interfaces of the annular space,prevent the oil base mud from contacting with the cementing slurry directly and pollute each other,improving the cementing environment of the annular interface and improving the cementing quality,it is necessary to select a spacer liquid technique suitable for oil based drilling fluid.There are YJC oil base mud flushing fluid and YJC mud flushing fluid for oil based drilling fluid used in Daqing oilfield.The temperature resistance of YJC oil base mud washing liquid can reach 180 degrees centigrade,but the highest temperature resistance of its aggravating system is only 100 degrees centigrade,and YJC can not meet the requirements of cementing construction when the slurry is aggravated at the temperature of 100 degrees C.On the other hand,the anti 150 and 180 C flushing fluid is suitable for water based drilling fluid.Therefore,a kind of high temperature oil based mud double effect spacer liquid is needed to enrich the cementing spacer liquid technology.In this paper,the research on the double effect admixture for the cementing of oil based mud in deep and ultra deep wells is studied,and various performance evaluation experiments are made and the admixtures with good scour effect are selected to ensure the good emulsification and penetration effect of the double effect spacer liquid.In view of the above mentioned problems,a double effect spacer liquid system has been carried out to form a 1.10 to 1.80g/cm3 double effect solution system of anti 150 centigrade.The surface active agent is used as a rinsing suspension agent and then injected into the flow type regulator to adjust its rheological property.The system can not only be applied to oil based drilling fluid,but also can be applied to water based drilling fluid cementing,which enriches the cementing spacer liquid technology.