Research Of Water-based Drilling Fluid Mixed With High Proportion Crude Technology

Water-based drilling fluid mixed with a high proportion crude techniques is a new type of drilling fluid system which is firstly proposed and successfully applied in the development of unconventional oil and gas reservoir in China..The system which overcomes the traditional oil-based drilling fluid pollution,high cost of the problem,has strong inhibition of anti-collapse performance,good lubrication,good resistance to high temperature.Therefore,it can meet the requirements of lubrication,anti-collapse,and carrying capacity of the extended reach well,horizontal well.Through the research,oil emulsifier for water-based drilling fluid mixed with a high proportion of crude was development.Lubricant was identified which mixed crude oil as the base oil.The formation reaserch of water base drilling fluid had been finished,and evaluated inhibitory,lubricity,anti-pollution performance.The performance of system was temperature of 150 degrees,the anti-bad soil 4%,salt 20%,permeability recovery value reached 90%.The indicators meet the field application requirements.So far,it has been successfully applied in Bonan Oilfield of Shengli Oilfield turbid product over 10 wells wells in rock blocks and Binnan oilfield offshore 435 beach bar sand block,which provided an effective method for the development of unconventional oil and gas reservoirs in Shengli oil field.In field application,high mixing oil and water-based drilling fluid system to overcome the large borehole long naked eyes,slim hole of long horizontal section,horizontal section sandstone and mudstone interbed.It shows superior performance in the construction of unconventional wells,which hit a number of Shengli Oilfield construction record.At last,based on the field application,the technology of high oil mixing ratio water base drilling fluid is established,which provides the guidance for the application of the system.