PROJECT: SiChuan rovince Science City ChunXi science and technology co., LTD’s BaoYe4XF Rotary Steering Drilling Service

DATE: Sep. 2015

LOCATION: Baojing County, Hunan Province

?Background?

Baoye4XF well located in Baojing County, Hunan Province. Geological condition is very complex in this area, and the lower formation is Paleozoic strata with many special features, like poor drillability, lots of faults and circulation loss zones, large and unstable dip angle, etc. Three wells were drilled by conventional drilling method at a earlier stage, but all failed in the reason of can not locate the reservoir.

Risk Analysis

 Risk of landing, Choicing of landing inclination

 Uncertainty of reservoir dip angle

 Uncertainty of lateral distribution

 Microfaults can not be recognised until be drilled

Solution

 Adjusting trajectory constantly according to the azimuth gamma cutting relation.

 Predicting the bit position based on the real-time log data analysis, and keeping the trajectory always in the high quality reservoir.

 Adjusting trajectory timely based on the azimuth gamma when near formation boundary or out of pay zone.

 Discussing with client in time, if drill to a fault or a structural mutation.

 Taking ROP, lithology and gas logging value as important reference.

Achievement

 Average ROP reached 8.88m/h, nearly three times of the design value(3m/h). Completed the three spud in section using one trip, shorten the drilling cycle greatly.

 Reservoir-encountered rate is 100%.