Patent ID: 8672033
Filing Date: 2014-03-18
Classification: C09K,C10M,C10N,E21B

Abstract:
1. A method of increasing the rate of production of reservoir fluid from a reservoir which includes a wellbore pump, wherein said wellbore pump is arranged to pump wellbore fluid within the wellbore to a surface, said method comprising the steps of: (a) selecting a wellbore which includes an associated wellbore pump, said wellbore pump being associated with a production tube and being arranged within a casing, wherein an annulus is defined between the casing and the pump/production tube, said annulus including reservoir fluid which has a hydrostatic head which is at least 15 m above the level of an inlet of the wellbore pump; (b) contacting a reservoir fluid in said annulus upstream of an inlet of the wellbore pump with a treatment formulation, wherein said treatment formulation comprises a first polymeric material which includes —O— moieties pendent from a polymeric backbone thereof, wherein the first polymeric material is optionally cross-linked; and (c) operating said wellbore pump to recover liquid hydrocarbons from the wellbore at a rate which is greater after contact with said treatment formulation compared to the rate of recovery of liquid hydrocarbons before contact with said treatment formulation (d) wherein, in step (b) said treatment formulation is caused to move from a first position, spaced from the inlet of the wellbore pump, towards a second position defined by the inlet of the wellbore pump, said treatment formulation being arranged to move along a fluid path which extends within the wellbore on moving towards said second position; (e) wherein a force is incident upon the treatment fluid to cause it to move between the said first and second positions, wherein at least 80% of said force is provided by gravity.