# US 2014/0151053 A1 · Hydrocarbons > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151053 A1 - Document ID: US20140151053A1 - Status: Published application - Kind: A1 - Application number: 14/172,169 - Filed: 2014-02-04 - Published: 2014-06-05 - Earliest claimed: 2007-06-15 - Assignees: Oilflow Solutions Holdings Limited - Applicants: Oilflow Solutions Holdings Limited - Inventors: Michael John Crabtree; Philip Fletcher; Jeffrey Forsyth - Web page: https://patentgrep.com/patent/US20140151053A1 ## CPC - C09K 8/588: characterised by the use of specific polymers {(polymeric surfactants C09K8/584)} - C09K 8/882: {obtained by reactions only involving carbon-to-carbon unsaturated bonds} - C09K 8/887: {containing cross-linking agents} - C10M 173/02: not containing mineral or fatty oils - E21B 43/25: Methods for stimulating production {(by vibrating earth formations E21B43/003)} - C10M 2209/062: Vinyl esters of saturated carboxylic or carbonic acids, e.g. vinyl acetate - C10N 2030/02: Pour-point; Viscosity index - E21B 43/127: {Adaptations of walking-beam pump systems} - E21B 43/128: {Adaptation of pump systems with down-hole electric drives} - Y02E 10/10: Geothermal energy - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - C10M: LUBRICATING COMPOSITIONS (well drilling compositions C09K8/02); USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION (mould release, i.e. separating, agents for metals B22C3/00, for plastics or substances in a plastic state, in general B29C33/56, for glass C03B40/02; textile lubricating compositions D06M11/00, D06M13/00, D06M15/00; immersion oils for microscopy G02B21/33) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - C10N: INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract An oil well includes a wellbore (2), below ground level (4), which extends to an oil reservoir (6). The wellbore includes a casing (8) within which is arranged a progressing cavity pump (PCP) 10 which includes an inlet (12) at its lower end and is connected at its upper end to production tube (14). An annulus (16) is defined between the pump (10)/tube (14) and the casing (8). The annulus communicates with the reservoir and includes a head (20) of reservoir fluid. A water based formulation which comprises an optionally cross-linked polyvinylalcohol can be poured down the annulus (16) and pass under gravity to the reservoir (6), immediately upstream of inlet (12). The formulation may improve the performance and efficiency of the pump (10) due to its ability to increase the mobility of the oil in the reservoir immediately upstream of the pump (10) and/or enhance the ability of the oil to enter the pump inlet. Furthermore, by improving mobility and/or reducing the level of back pressure when the oil enters the pump inlet (or any other constriction) the rate of flow of oil from the reservoir into the wellbore may be increased resulting in an increased rate of oil production. ## Claims ### Claim at position 1 1-20. (canceled) ### Claim 21 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. ### Claim 22 (depends on 21) The method according to claim 21, the method comprising lowering the height of said hydrostatic head of reservoir fluid in said wellbore annulus. ### Claim 23 (depends on 21) The method according to claim 21, wherein said hydrostatic head is at least 30 m above the level of the inlet of the wellbore pump. ### Claim 24 (depends on 21) The method according to claim 21, 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. ### Claim 25 (depends on 21) The method according to claim 21, wherein said treatment formulation is introduced into the wellbore from an input position, wherein the input position is on an imaginary vertical line which is spaced horizontally from the inlet of the wellbore by a distance of less than 500 m. ### Claim 26 (depends on 21) The method according to claim 21, wherein a filtration device is associated with the wellbore, upstream of the wellbore pump. ### Claim 27 (depends on 21) The method according to claim 21, wherein said wellbore pump is selected from a progressing cavity pump, a beam pump and a centrifugal pump. ### Claim 28 (depends on 21) The method according to claim 21, wherein in step (a) the method comprises: selecting a wellbore having a hydrostatic head in the annulus which is less than 300 m above said level; or selecting a wellbore associated with a reservoir which is capable of yielding more oil if the rate of flow through the wellbore can be increased; or selecting a wellbore having a wellbore pump having a volumetric efficiency of less than 60%; or selecting a wellbore wherein oil in the wellbore has a viscosity in the range 2000 to 50000 cp. ### Claim 29 (depends on 21) The method according to claim 21, wherein said treatment formulation includes at least 0.1 wt % of said optionally cross-linked first polymeric material and less than 5 wt % of said optionally cross-linked first polymeric. ### Claim 30 (depends on 21) The method according to claim 21, wherein said treatment formulation includes 0.1 to 3 wt % of said optionally cross-linked polymeric material; 0 to 20 wt % of dissolved or dispersed components in addition to said optionally cross-linked polymeric material; 77 to 99.9 wt % water. ### Claim 31 (depends on 21) The method according to claim 21, wherein said optionally cross-linked first polymeric material makes up at least 98 wt % of active materials in said treatment formulation. ### Claim 32 (depends on 21) The method according to claim 21, wherein said first polymeric material includes a moiety ### Claim 33 (depends on 21) The method according to claim 21, wherein said first polymeric material includes a plurality of functional groups selected from hydroxyl and acetate groups. ### Claim 34 (depends on 21) The method according to claim 21, wherein said first polymeric material includes a multiplicity of hydroxyl groups pendant from a polymeric backbone; and also includes a multiplicity of acetate groups pendant from the polymeric backbone. ### Claim 35 (depends on 21) The method according to claim 21, wherein said first polymeric material includes a vinyl alcohol moiety. ### Claim 36 (depends on 21) The method according to claim 21, wherein said first polymeric material comprises a 5 to 95% hydrolysed polyvinyl acetate. ### Claim 37 (depends on 21) The method according to claim 21, wherein said first polymeric material is not cross-linked. ### Claim 38 (depends on 21) The method according to claim 21, wherein use of said treatment formulation increases the rate of flow of fluid passing from the reservoir into the wellbore. ### Claim 39 A system associated with a wellbore, wherein said wellbore is associated with a reservoir which is producing oil and which is capable of yielding more oil if the rate of flow through the wellbore can be increased, the system comprising: a receptacle above the surface of the ground, the receptacle containing a treatment formulation which comprises a first polymeric material which includes —O— moieties pendent from a polymeric backbone thereof, wherein the first polymeric material is optionally cross-linked; conduit means extending from the receptacle and being arranged to deliver treatment formulation from the receptacle to a position wherein it contacts reservoir fluid, wherein the treatment formulation is introduced into the formation at a rate of at least 0.1 litres/minutes and wherein the wellbore includes a wellbore pump arranged to pump wellbore fluid within the wellbore to said surface. ### Claim 40 (depends on 21) The method according to claim 21, wherein said first polymeric material is not cross-linked and comprises 70 to 95% hydrolysed polyvinylacetate. ### Claim 41 A method of improving the volumetric efficiency of a wellbore pump associated with a wellbore, wherein a 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 a wellbore pump having a volumetric efficiency of less than 60%; and b) contacting a reservoir fluid 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; c) whereby the volumetric efficiency of the wellbore pump associated with the reservoir is improved after contact with said treatment formulation. ### Claim 42 A method of increasing the rate of production of reservoir fluid from a reservoir which includes a wellbore pump 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; (b) contacting a reservoir fluid 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; wherein the ratio of the volume of reservoir fluid to the volume of treatment formulation is in the range 70:30 (reservoir fluid:formulation) to 85:15; 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. ### Claim 43 (depends on 21) The method according to claim 21, wherein the ratio of the volume of reservoir fluid to the volume of treatment formulation is in the range of 70:30 (reservoir fluid:formulation) to 85:15. ### Claim 44 A method of increasing the rate of production of reservoir fluid from a reservoir which includes a wellbore pump 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; (b) contacting a reservoir fluid 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; wherein the treatment formulation is introduced into the formation at a rate of at least 0.1 litres/minute; 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.