Downhole sand trap
A solids trap module for an electrical submersible pump (ESP) of a wellbore is provided. The module includes a solids buffer and a fluid passage, the fluid passage having a first segment configured to redirect a fluid in a first angular direction relative to an axial axis, and a second segment configured to redirect at least a portion of the redirected fluid flow in a second angular direction different than the first angular direction. The first segment, the second segment, and the solids buffer are configured to cooperate to cause settling of solids entrained by the fluid flowing through the solids trap module during a period when the ESP does not operate and to re-entrain settled solids into the fluid flowing through the solids trap module when the ESP is operating.
1 . A solids trap module for an electrical submersible pump (ESP) of a wellbore, comprising:
a body;
a flow modifier configured to be a solid obstruction positioned axially within the body and statically affixed to the body via one or more ribs or spokes,
wherein an uphole-facing surface of the flow modifier forms a solids buffer,
wherein the flow modifier is in the form of a rounded cone, an apex of the rounded cone having a spherical cap positioned downhole and a base of the rounded cone forming the solids buffer; and
a fluid passage defined by an inner surface of the body and an outer surface of the flow modifier, the fluid passage comprising:
a first segment configured to redirect a fluid flowing through the solids trap module in a first angular direction relative to an axial axis of the solids trap module to form a redirected fluid flow; and
a second segment, fluidly connected to the first segment, configured to redirect at least a portion of the redirected fluid flow in a second angular direction different than the first angular direction to pass over at least a portion of the solids buffer,
wherein, when the ESP is not operating, the first segment, the second segment, the body, and the flow modifier are configured to cooperate to cause settling of solids entrained by the fluid onto the solids buffer of the flow modifier as the fluid flows downhole through the solids trap module, and
wherein, when the ESP is operating, the first segment, the second segment, the body, and the flow modifier are configured to cooperate to cause the solids settled on the solids buffer to be re-entrained into the fluid as the fluid flows uphole through the solids trap module.
2 . The solids trap module of claim 1 , wherein a first cross-sectional area of the second segment at a first point nearest the axial axis of the solids trap module is smaller than a second cross-sectional area of the second segment at a second point furthest from the axial axis of the solids trap module.
3 . The solids trap module of claim 1 , wherein a first cross-sectional area of the first segment at a first point nearest the axial axis of the solids trap module is greater than a second cross-sectional area of the first segment at a second point furthest from the axial axis of the solids trap module.
4 . The solids trap module of claim 1 , wherein the solids buffer comprises a recess configured to accumulate settled solids.
5 . The solids trap module of claim 1 , wherein the one or more ribs or spokes affix the rounded cone to the inner surface of the solids trap module.
6 . The solids trap module of claim 5 , wherein at least one of the one or more ribs or spokes are configured to impart rotation to the fluid flowing through the solids trap module.
7 . The solids trap module of claim 1 , wherein a first external surface of the solids trap module is configured to engage with a second external surface of a second solids trap module to enable stacking of the solids trap module with another solids trap module.
8 . The solids trap module of claim 7 , wherein the solids trap module comprises a first register having a complementary shape to a register of the second solids trap module, and configured to concentrically align the solids trap module with the second solids trap module in a stacked configuration.
9 . The solids trap module of claim 1 , wherein the solids trap module comprises a geometric feature configured to angularly align the solids trap module with another solids trap module.
10 . The solids trap module of claim 1 , wherein the solids trap module is unitarily formed by one of casting, injection molding, and three-dimensional printing.
11 . A wellbore, comprising:
a one-way flapper valve;
the solids trap module according to claim 1 positioned uphole of a one way flapper valve.
12 . The wellbore according to claim 11 , further comprising: an electric submersible pump located down hole of the solids trap module.