Wellhead sand separation system

A system, comprising:

• a separator configured to receive a mixture of solids and fluid from a wellhead;
• a first accumulator configured to receive the solids separated from the mixture by the separator;
• a second accumulator configured to receive the solids from the first accumulator, wherein the second accumulator is maintained at a relatively low pressure relative to the first accumulator, such that a pressure differential causes the solids to move from the first accumulator to the second accumulator;
• an isolation valve between the first and second accumulators, wherein the isolation valve is configured to be opened to permit the movement of the solids from the first accumulator to the second accumulator, and to be closed to permit fluid communication between the first and second accumulators;
• and
• a pump configured to deliver a liquid to the second accumulator, so as to remove the solids therefrom.

A method, comprising:

• receiving a mixture of solids and fluid from a wellhead in a separator;
• removing at least some of the solids from the mixture using the separator;
• storing the removed solids in a first accumulator;
• providing a high-pressure, relative to a pressure in the first accumulator, fluid to a transfer of rotation (TOR) device coupled to the first accumulator, wherein providing the high-pressure fluid to the TOR device causes the removed solids to be evacuated from the first accumulator;
• delivering the removed solids from the TOR device to a second accumulator;
• and
• delivering the removed solids from the second accumulator to a sand disposal hopper, a sand cleaning system, or both.