Fluid pumping apparatus
View Patent ↗A method and apparatus suitable for coupling seismic or other downhole sensors to a borehole wall in high temperature and pressure environments. In one embodiment, one or more metal bellows mounted to a sensor module are inflated to clamp the sensor module within the borehole and couple an associated seismic sensor to a borehole wall. Once the sensing operation is complete, the bellows are deflated and the sensor module is unclamped by deflation of the metal bellows. In a further embodiment, a magnetic drive pump in a pump module is used to supply fluid pressure for inflating the metal bellows using borehole fluid or fluid from a reservoir. The pump includes a magnetic drive motor configured with a rotor assembly to be exposed to borehole fluid pressure including a rotatable armature for driving an impeller and an associated coil under control of electronics isolated from borehole pressure.
1. An apparatus for pumping fluid within a borehole, comprising:
a housing;
a barrier wall dividing an interior of the housing into a first cavity and a second cavity, wherein the second cavity is hermetically sealed;
a laterally extendable sensor coupled with an inflatable bellows
a rotor assembly comprising an armature rotatably mounted within the first cavity, carrying at least one permanent magnet and having an impeller secured thereto;
a plurality of electromagnetic coils disposed circumferentially about the armature;
a static shell substantially disposed about the rotor assembly, wherein a portion of the static shell is disposed between the electromagnetic coils and the armature, and wherein the static shell defines a common volume about the armature and the impeller such that fluid may flow within the common volume about both the armature and the impeller; and
electronic controls contained within the second cavity and configured to fire the electromagnetic coils in an orbital manner.
2. The apparatus of claim 1 , further comprising at least sealed wire feed coupled between the electronic controls and the plurality of electromagnetic coils.
3. The apparatus of claim 1 , wherein the static shell comprises a material substantially transparent to magnetic field emissions.
4. The apparatus of claim 3 , wherein the static shell comprises austenite stainless steel.
5. The apparatus of claim 1 , further comprising an inlet from the exterior of the housing into the first cavity.
6. The apparatus of claim 5 , wherein the inlet further comprises a selectively closeable valve.
7. The apparatus of claim 5 , wherein the common volume defined by the static shell is in communication with the first cavity.
8. The apparatus according to claim 5 , further comprising an expandable fluid reservoir contained within the first cavity of the housing, wherein an inlet is defined in the static shell at a location adjacent the impeller and wherein the inlet is coupled with the expandable fluid reservoir.
9. The apparatus of claim 8 , wherein the inlet further comprises a selectively closeable valve.
10. The apparatus of claim 1 , further comprising a supply conduit having a first end in communication with the common volume defined by the static shell at a location adjacent the impeller, the supply conduit also having a second end extending to a remote location exterior to the housing.
11. The apparatus of claim 1 , wherein the plurality of electromagnetic coils are disposed within the first cavity.