An apparatus for mixing multiphase fluids, comprising: a fluid mixing device including: a pipe having a pipe wall and an axial bore that extends from an inlet of the pipe to an outlet of the pipe for conveying fluids through the pipe from the inlet of the pipe to the outlet of the pipe; a sleeve disposed about the pipe; a cavity provided between an exterior surface of the pipe and an interior surface of the sleeve, wherein the cavity and the axial bore of the pipe are in fluid communication with one another via multiple openings angled through the pipe wall, and the multiple openings through the pipe wall are located between the inlet of the pipe and the outlet of the pipe; an outlet tap connected to the pipe at a location between the inlet of the pipe and the outlet of the pipe so as to receive, through the pipe wall from the axial bore, a portion of the fluids conveyed through the pipe; and an inlet tap connected to the sleeve, wherein the outlet tap is positioned downstream of the inlet tap and is in fluid communication with the inlet tap; and a pump coupled in fluid communication between the outlet tap and the inlet tap, wherein the pump is configured to draw the portion of the fluids conveyed through the pipe from the axial bore via the outlet tap and to pump the portion of the fluids drawn from the axial bore into the cavity via the inlet tap, and the opening through the pipe wall is configured to jet the portion of the fluids from the cavity into the axial bore to mix the fluids conveyed through the pipe; wherein the multiple openings include at least two openings having interior ends at the interior of the pipe wall that are axially offset from one another, wherein one of the multiple openings is angled toward the direction of flow through the axial bore and another of the multiple openings is angled away from the direction of flow through the axial bore. a fluid mixing device including: a pipe having a pipe wall and an axial bore that extends from an inlet of the pipe to an outlet of the pipe for conveying fluids through the pipe from the inlet of the pipe to the outlet of the pipe; a sleeve disposed about the pipe; a cavity provided between an exterior surface of the pipe and an interior surface of the sleeve, wherein the cavity and the axial bore of the pipe are in fluid communication with one another via multiple openings angled through the pipe wall, and the multiple openings through the pipe wall are located between the inlet of the pipe and the outlet of the pipe; an outlet tap connected to the pipe at a location between the inlet of the pipe and the outlet of the pipe so as to receive, through the pipe wall from the axial bore, a portion of the fluids conveyed through the pipe; and an inlet tap connected to the sleeve, wherein the outlet tap is positioned downstream of the inlet tap and is in fluid communication with the inlet tap; and a pipe having a pipe wall and an axial bore that extends from an inlet of the pipe to an outlet of the pipe for conveying fluids through the pipe from the inlet of the pipe to the outlet of the pipe; a sleeve disposed about the pipe; a cavity provided between an exterior surface of the pipe and an interior surface of the sleeve, wherein the cavity and the axial bore of the pipe are in fluid communication with one another via multiple openings angled through the pipe wall, and the multiple openings through the pipe wall are located between the inlet of the pipe and the outlet of the pipe; an outlet tap connected to the pipe at a location between the inlet of the pipe and the outlet of the pipe so as to receive, through the pipe wall from the axial bore, a portion of the fluids conveyed through the pipe; and an inlet tap connected to the sleeve, wherein the outlet tap is positioned downstream of the inlet tap and is in fluid communication with the inlet tap; and a pump coupled in fluid communication between the outlet tap and the inlet tap, wherein the pump is configured to draw the portion of the fluids conveyed through the pipe from the axial bore via the outlet tap and to pump the portion of the fluids drawn from the axial bore into the cavity via the inlet tap, and the opening through the pipe wall is configured to jet the portion of the fluids from the cavity into the axial bore to mix the fluids conveyed through the pipe; wherein the multiple openings include at least two openings having interior ends at the interior of the pipe wall that are axially offset from one another, wherein one of the multiple openings is angled toward the direction of flow through the axial bore and another of the multiple openings is angled away from the direction of flow through the axial bore.