The present invention relates to a barrier testing method for testing a production casing in a borehole (4). The method is applied before initiating production in a well and comprises the steps of connecting a drill pipe (10) with a first end (20) of a first production casing having annular barriers (17), which annular barriers (17) comprise a tubular part forming part of the casing and an expandable sleeve circumferenting the tubular part, thereby defining an expandable space; inserting the drill pipe (10) and the first production casing (3) via a drill head (6) arranged at a top (7) of the well into an intermediate casing (11) extending in a first part (18) of the borehole (4) closest to the top of the well and at least part of the first production casing into a second part (19) of the borehole; sealing a second end (21) of the first production casing (3); pressurizing the first production casing (3) from within and expanding one or more of the expandable sleeves (22) of the annular barriers (17) to abut a wall of the borehole; pressurizing the first production casing (3) from within to a predetermined pressure; and testing the first production casing (3) after expansion by measuring if the predetermined pressure is kept constant during a predetermined time period. Furthermore, the invention relates to a completion system for oil production from a well and to an oil production facilitated by the method barrier testing method.

The present invention relates to a barrier testing method for testing a production casing in a borehole (4). The method is applied before initiating production in a well and comprises the steps of connecting a drill pipe (10) with a first end (20) of a first production casing having annular barriers (17), which annular barriers (17) comprise a tubular part forming part of the casing and an expandable sleeve circumferenting the tubular part, thereby defining an expandable space; inserting the drill pipe (10) and the first production casing (3) via a drill head (6) arranged at a top (7) of the well into an intermediate casing (11) extending in a first part (18) of the borehole (4) closest to the top of the well and at least part of the first production casing into a second part (19) of the borehole; sealing a second end (21) of the first production casing (3); pressurizing the first production casing (3) from within and expanding one or more of the expandable sleeves (22) of the annular barriers (17) to abut a wall of the borehole; pressurizing the first production casing (3) from within to a predetermined pressure; and testing the first production casing (3) after expansion by measuring if the predetermined pressure is kept constant during a predetermined time period. Furthermore, the invention relates to a completion system for oil production from a well and to an oil production facilitated by the method barrier testing method.

System and methods of simulating fluid production in a multi-reservoir system with a common surface network are presented. An equation of state (EOS) characterization of fluids is matched with a delumped EOS model representing different components of the fluids for each reservoir within the multi-reservoir system. Fluid production in the multi-reservoir system is simulated for at least one simulation point in the common surface network, based in part on the delumped EOS model for each reservoir. If the fluids produced during the simulation at the simulation point are mixed fluids from different reservoirs, one or more interpolation tables representing the mixed fluids are generated and properties of the mixed fluids are calculated based on the generated interpolation tables. Otherwise, the properties of the fluids are calculated using the delumped EOS model corresponding to the reservoir from which the fluids are produced.

System and methods of simulating fluid production in a multi-reservoir system with a common surface network are presented. An equation of state (EOS) characterization of fluids is matched with a delumped EOS model representing different components of the fluids for each reservoir within the multi-reservoir system. Fluid production in the multi-reservoir system is simulated for at least one simulation point in the common surface network, based in part on the delumped EOS model for each reservoir. If the fluids produced during the simulation at the simulation point are mixed fluids from different reservoirs, one or more interpolation tables representing the mixed fluids are generated and properties of the mixed fluids are calculated based on the generated interpolation tables. Otherwise, the properties of the fluids are calculated using the delumped EOS model corresponding to the reservoir from which the fluids are produced.

A formation treatment fluid may include a wettability alteration agent, a solvent, an injection gas, and an optional foaming agent. The wettability alteration agent may include a fluorinated surfactant, a silicon-based surfactant, charged nanoparticles partially modified with fluorine containing groups, or combinations thereof. Methods for altering a hydrocarbon-bearing reservoir surface wettability may include providing the formation treatment fluid, injecting the formation treatment fluid into the hydrocarbon-bearing reservoir, and recovering fluids produced from the hydrocarbon-bearing reservoir.

A method of acidizing a formation penetrated by a wellbore that includes the steps of injecting into the wellbore at a pressure below formation fracturing pressure a treatment fluid that includes a gelling fluid including a gelling agent and a hydrophobically-modified associative polymer, and an aqueous acid; and allowing the treatment fluid to acidize the formation.

A method of acidizing a formation penetrated by a wellbore that includes the steps of injecting into the wellbore at a pressure below formation fracturing pressure a treatment fluid that includes a gelling fluid including a gelling agent and a hydrophobically-modified associative polymer, and an aqueous acid; and allowing the treatment fluid to acidize the formation.

A method and apparatus for producing hydrocarbons from a subterranean formation. A first well is provided in the formation, the first well being separated by an isolating material into at least a first and second zone, the first zone being substantially isolated from the second zone. A second well is provided in the formation. The second well is separated by an isolating material into at least a first and second zone, the first zone being substantially isolated from the second zone. A first fracture is provided in the formation, the first fracture extending substantially between the first zones. A second fracture is provided in the formation, the second fracture extending substantially between the second zones of the first and second wells. A fluid is injected into the formation from the first zone in the first well. Hydrocarbons are produced at the second zone of the second well.

The disclosure provides a method of treating a subterranean formation penetrated by a wellbore. The method includes introducing a gas phase gas into fractures of the subterranean formation extending from the wellbore, followed by introducing a carrier fluid into the subterranean formation under sufficient pressure to fracture a portion of the subterranean formation and release hydrocarbons from the subterranean formation. The gas phase gas occupies the fractures at a sufficient pressure to cause the carrier fluid to be diverted to additional fractures of the subterranean formation defined by the portion.

Various embodiments disclosed relate to methods of stimulating a subterranean formation using an acid precursor composition. In various embodiments, the present invention provides a method of stimulating a subterranean formation. The method includes placing a fracturing composition in a subterranean formation. The method includes hydraulically fracturing the subterranean formation with the fracturing composition, to form at least one fracture and a spent fracturing composition. The method includes flushing the subterranean formation. The method includes placing an acid precursor composition in the subterranean formation, the acid precursor composition including an acid precursor. The method includes forming an acid from the acid precursor. The method also includes acidizing the subterranean formation with the formed acid.