A. Artificial Lift system for Horizontal oil wells
The prevalent artificial lift modes in ONGC are Gas Lift, SRP, and ESP & PCP. Jet pumps were also tried, but have not been used extensively.
i) The challenges include
a) Mechanical failures of lift equipment due higher deviation resulting in higher stresses.
b) Operational inefficiencies resulting due to higher propensity of phase segregation in horizontal well bores.
c) Non-availability of indigenous lift equipment of requisite quality catering to rigorous functional requirements.
ii) Boundary conditions for arriving at innovative solutions for artificial lift equipment for horizontal wells.
a) Flow rates
b) Water cut
d) API gravity
f) Wax / Asphaltene
10 – 5000 blpd
0 – 95 %
10 – 45 deg
Up to 3000 Cp
Up to 25% by wt
Up to 10% vol ( with sand control measures ), up to 20% ( without sand control measures )
c) Dog leg severity
Up to 3000 m
0 – 90 Deg
0 – 10
5 ½” / 7” / 9 5/8”
2 7/8” / 3 ½”
|3||Pump Intake conditions
175 Deg C
a) Down hole / surface sensors
b) Remote data acquisition system
a) Conventional / alternate energy ( solar etc )
B. Artificial Lift system for horizontal gas wells
i) Challenges include decline in vertical lift performance because of fall in reservoir pressure. Innovation challenge is to boost the fluid (gas + water + condensate) pressure at down hole to be able to reach surface at desired pressure.
ii) Boundary conditions
|1||Pressure Boosting requirement||10 – 120 bar & 5 – 40 bar|
up to 0.6 MMSCMD
up to 200 m3/day
up to 100 m3/day
|3||Temperature||120 Deg C|
|4||Gas quality||H2S – up to 200 ppm, Co2 5 – 6 %|