Drilling Technologies for Well Caishi-P1 in Shengli Oilfield

In order to provide a better platform for testing of various wellheads,downhole instruments and drilling and recovery tools,Shengli Oilfield designed the Well Caishi-P1.It is a horizontal well,660.4 mm in the first drilling section,and 444.5 mm in the second drilling section.It faces challenges such as difficult cutting carrying,poor borehole stability,low penetration rate,high requirements on trajectory control and difficult completion,etc.Finally,we succeeded by using a series of measures,including the selection of GJT115GC cone bit,increase of 228.6 mm drill collars,increase of flow rate,reuse of used drilling fluids in first-spudding section,use of inhibitive drilling fluids in the second-spudding section,change of positive displacement mud motors in time,and wiper trip with strongly rigid BHA.The results show that the well trajectory is very good,and the maximum overall angle change rate is only 12.78°/100m,and the average penetration rate was 10.94 m/h.The wellbore was stable without any downhole accident.The 339.7 mm production casing was running smoothly to the depth of 1 691.15 m.Both the wellbore quality and cementing quality are satisfactory.The success of Well Caishi-P1 shows that the drilling technologies are feasible,and it can be a reference for the safe drilling of large size horizontal wells with high quality in Shengli Oilfield.