Withdrawal of gases and liquids from an in situ oil shale retort

Apparatus for recovering liquid and gaseous products from an in situ oil shale retort formed within a retort site in a subterranean formation containing oil shale, the apparatus comprising:

• a fragmented permeable mass of formation particles containing oil shale formed within the retort site, wherein a retorting zone is established in an upper portion of the fragmented mass and advanced through the fragmented mass for producing liquid and gaseous products of retorting;
• a production level void spaced below the fragmented mass;
• a zone of unfragmented formation between a lower portion of the fragmented mass and the production level void;
• at least one liquid outlet line extending from a lower portion of the fragmented mass through said zone of unfragmented formation and into the production level void for conducting liquid products to the production level void;
• at least one gas outlet line extending from a lower portion of the fragmented mass through said zone of unfragmented formation and into the production level void for conducting gaseous products to the production level void separate from the liquid products;
• means for withdrawing from the production level void liquid products conducted thereto by such a liquid outlet line;
• and
• means for withdrawing from the production level void gaseous products conducted thereto by such a gas outlet line.

In an in situ oil shale retort formed within a retort site in a subterranean formation containing oil shale, such an in situ retort containing a fragmented permeable mass of formation particles containing oil shale, wherein a retorting zone established in an upper portion of the fragmented mass and advanced through the fragmented mass produces liquid and gaseous products of retorting, and further including a production level void spaced below a lower boundary of the fragmented mass, and means within the production level void for withdrawing liquid products conducted from the fragmented mass to the production level void, the improvement comprising:

• a gas barrier of unfragmented formation between the lower boundary of the fragmented mass and the production level void;
• a plurality of gas outlet means distributed across a horizontal cross section of the fragmented mass for conducting all of the gaseous products from distributed portions of the fragmented mass through the gas barrier to the production level void;
• gas withdrawal means communicating with the gas outlet means in the production level void for withdrawing from the production level void the gaseous products conducted thereto by the gas outlet means;
• and
• means for withdrawing liquid products from the production level void separately from the gaseous products.

In an in situ oil shale retort formed within a retort site in a subterranean formation containing oil shale, such an in situ retort containing a fragmented permeable mass of formation particles containing oil shale, wherein a retorting zone established in an upper portion of the fragmented mass and advanced through the fragmented mass produces liquid and gaseous products of retorting, and further including a production level void spaced below a lower boundary of the fragmented mass, and means within the production level void of withdrawing liquid products conducted from the fragmented mass to the production level void, the improvement comprising:

• a gas barrier of unfragmented formation between the lower boundary of the fragmented mass and the production level void;
• a plurality of gas outlet means distributed across a horizontal cross section of the fragmented mass and sealed to unfragmented formation within the gas barrier for conducting gaseous products from the fragmented mass through the gas barrier to the production level void;
• a gas withdrawal manifold communicating with such gas outlet means within the production level void;
• means for withdrawing gaseous products from the manifold for withdrawing from the production level void gaseous products conducted thereto by the gas outlet means;
• and
• separate valve means in the production level void between each gas outlet means and the manifold for use in independently controlling flow of gas from the fragmented mass through the separate gas outlet means.

In an in situ oil shale retort formed within a retort site in a subterranean formation containing oil shale, such an in situ retort containing a fragmented permeable mass of formation particles containing oil shale, wherein a retorting zone established in an upper portion of the fragmented mass and advanced through the fragmented mass produces liquid and gaseous products of retorting, and further including a production level void spaced below a lower boundary of the fragmented mass, and means within the production level void for withdrawing liquid products conducted from the fragmented mass to the production level void, the improvement comprising:

• a gas barrier of unfragmented formation between the lower boundary of the fragmented mass and the production level void;
• a plurality of gas outlet means distributed across a horizontal cross section of the fragmented mass for conducting gaseous products from the fragmented mass through the gas barrier to the production level void;
• liquid/gas separation means communicating with the gas outlet means in the fragmented mass for directing flow of gaseous products into the gas outlet means and for inhibiting flow of liquid products into the gas outlet means;
• and
• gas withdrawal means communicating with the gas outlet means in the production level void for withdrawing from the production level void gaseous products conducted thereto by the gas outlet means.

In an in situ oil shale retort formed within a retort site in a subterranean formation containing oil shale, such an in situ retort containing a fragmented permeable mass of formation particles containing oil shale, wherein a retorting zone established in an upper portion of the fragmented mass and advanced downwardly through the fragmented mass produces liquid and gaseous products of retorting;

• and further including a production level void spaced below a lower boundary of the fragmented mass, and means within the production level void for withdrawing liquid products conducted from the fragmented mass to the production level void, the improvement comprising:
• a gas barrier of unfragmented formation between the lower boundary of the fragmented mass and the production level void;
• gas outlet means communicating with a lower portion of the fragmented mass and extending through said gas barrier into the production level void;
• gas withdrawal means communicating with the gas outlet means for withdrawing from the production level void gaseous products conducted thereto through the gas outlet means;
• and
• liquid/gas separation means in the fragmented mass adjacent an inlet to such gas outlet means for inhibiting flow of liquid products from the fragmented mass into the inlet of such gas outlet means and for permitting gas to flow from the fragmented mass into the inlet of such gas outlet means.

Apparatus for recovering liquid and gaseous products from an in situ oil shale retort formed within a retort site in a subterranean formation containing oil shale, such an in situ oil shale retort comprising a fragmented permeable mass of formation particles containing oil shale, wherein a retorting zone established within the fragmented mass and advanced through the fragmented mass produces liquid and gaseous products of retorting, the apparatus comprising:

• a production level void spaced below a lower boundary of the fragmented mass;
• a zone of unfragmented formation providing a gas barrier between the lower boundary of the fragmented mass and the production level void, the zone of unfragmented formation forming a floor adjacent a lower portion of the fragmented mass, the floor being sloped downwardly to at least one region of lower elevation than an adjacent region of the floor so that liquid products of retorting can flow across the floor toward said region of lower elevation;
• at least one liquid outlet line having an inlet at such a region of lower elevation, such liquid outlet line extending through the zone of unfragmented formation into the production level void;
• a sump in the production level void communicating with the liquid outlet line for containing liquid products withdrawn from the fragmented mass through the liquid outlet line;
• gas outlet means in a lower portion of the fragmented mass and extending through the zone of unfragmented formation into the production level void, the inlet to such gas outlet means being at a higher elevation in the fragmented mass than said region of lower elevation;
• gas withdrawal means communicating with the gas outlet means in the production level void for withdrawing from the production void gaseous products conducted thereto through the gas outlet means;
• and
• liquid/gas separation means within the fragmented mass for inhibiting flow of liquid products from the fragmented mass into the gas outlet means and for permitting gaseous products to flow from the fragmented mass into the gas outlet means.

In an in situ oil shale retort formed within a retort site in formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale, wherein a retorting zone established within the fragmented mass and advanced downwardly through the fragmented mass produces liquid and gaseous products of retorting;

• and further including a production level void spaced below a lower boundary of the fragmented mass, a zone of unfragmented formation being between the production level void and the lower boundary of the fragmented mass, and means within the production level void for withdrawing liquid products conducted thereto from the fragmented mass, the improvement comprising:
• a plurality of separate gas outlet means distributed across a horizontal cross-section of a lower portion of the fragmented mass and extending downwardly through the zone of unfragmented formation into the production level void;
• separate valve means within the production level void for separately controlling flow of gas through each of the gas outlet means;
• means communicating with the gas outlet means in the production level void for withdrawing from the production level void gaseous products conducted thereto through the gas outlet means;
• and
• means for separating liquid from gas within the fragmented mass prior to entry of separated gas into such gas outlet means.

A method for recovering liquid and gaseous products from an in situ oil shale retort formed within a retort site in a subterranean formation containing oil shale, such an in situ oil shale retort containing a fragmented permeable mass of formation particles containing oil shale, wherein a retorting zone established in an upper portion of the fragmented mass and advanced downwardly through the fragmented mass produces liquid and gaseous products of retorting, the method comprising the steps of:

• providing a production level void at a level spaced below a lower boundary of the fragmented mass, leaving a zone of unfragmented formation between the production level void and the lower boundary of the fragmented mass;
• conducting liquid products of retorting downwardly to the production level void;
• providing a plurality of mutually spaced apart gas outlet means across a horizontal cross-section of a lower portion of the fragmented mass;
• conducting gaseous products from the spaced apart gas outlet means through separate gas outlet lines extending downwardly through the zone of unfragmented formation into the production level void;
• separately controlling the flow of gas through each gas outlet line from locations within the production level void for selectively withdrawing gas from the gas outlet lines for balancing the flow of gas from the top to the bottom of the fragmented mass;
• and
• separating liquid from gas within the fragmented mass prior to such gas flowing through such gas outlet lines.

An in situ oil shale retort formed within a retort site having side boundaries of unfragmented formation in a subterranean formation containing oil shale comprising:

• a fragmented permeable mass of formation particles containing oil shale within the retort;
• a production level drift spaced below the fragmented mass;
• a lower zone of unfragmented formation between a lower portion of the fragmented mass and the production level drift;
• a central vertically extending product withdrawal passage through the lower zone of unfragmented formation in the center of the retort site;
• a plurality of additional vertically extending product withdrawal passages through the lower zone of unfragmented formation, each of the additional product withdrawal passages being between the central product withdrawal passage and the middle of a side boundary of the retort site;
• and
• means at the top of each such product withdrawal passage for inhibiting particles from the fragmented mass from entering such product withdrawal passage.

An in situ oil shale retort formed within a retort site having side boundaries of unfragmented formation in a subterranean formation containing oil shale, comprising:

• a fragmented permeable mass of formation particles containing oil shale within the retort, the fragmented mass being substantially square in horizontal cross section;
• a production level drift spaced below the fragmented mass;
• a lower zone of unfragmented formation between a lower portion of the fragmented mass and the production level drift;
• at least five product withdrawal passages mutually spaced apart in a cross-shaped pattern across the lower portion of the fragmented mass in the retort, each of such product withdrawal passages extending from the bottom of the fragmented mass through the lower zone of unfragmented formation to the production level drift for conducting products of retorting from the fragmented mass to the production level drift, one of the product withdrawal passages being in the center of the horizontal cross section of the retort, each of the other product withdrawal passages being between the center passage and the middle of one of the side boundaries;
• means at the top of each of such product withdrawal passages for inhibiting particles from the fragmented mass from entering such product withdrawal passage;
• and
• means for withdrawing products of retorting from the production level drift.