TECHNICAL FIELD

The present disclosure relates generally to subterranean field operations, and more specifically to assemblies used to collect core samples in a subterranean wellbore.

BACKGROUND

During subterranean field operations, data is collected to determine the composition of the formation that is being developed. Much of this data is based on measurements made by sensors that are downhole, and so calculations are often used to provide estimates. While devices and models are highly sophisticated, it is sometimes desirable to collect physical core samples that are relatively uncontaminated (for example, by circulating fluid). These core samples can be used to provide valuable information about the formation at a certain depth in the wellbore.

SUMMARY

In general, in one aspect, the disclosure relates to a subterranean coring assembly. The subterranean coring assembly can include a body having at least one wall that forms a cavity, where the cavity has a top end and a bottom end. The subterranean coring assembly can also include a first flow regulating device movably disposed within the cavity, where the first flow regulating device is configured to move from a first default position to a first operating position within the cavity based on first flow characteristics of fluid that flows into the top end of the cavity toward the bottom end of the cavity.

In another aspect, the disclosure can generally relate to a coring bottom-hole assembly (BHA). The coring BHA can include an upstream section having a first coupling feature disposed on a distal end thereof. The coring BHA can also include a downstream section having a catcher assembly, a core head, and a second coupling feature disposed on a proximal end thereof. The coring BHA can further include a subterranean coring assembly coupled to and disposed between the upstream portion and the downstream portion. The subterranean coring assembly can include a body having at least one wall that forms a cavity, where the cavity has a top end and a bottom end, where the top end includes an upstream section coupling feature, and where the bottom end includes a downstream section coupling feature. The subterranean coring assembly can also include a first flow regulating device movably disposed within the cavity, where the first flow regulating device is configured to move from a first default position to a first operating position within the cavity based on first flow characteristics of fluid that flows through the upstream section into the top end of the cavity toward the downstream section. The first operating position can correspond to a first mode of operation.

In another yet aspect, the disclosure can generally relate to a method for performing a subterranean coring operation in a wellbore. The method can include receiving fluid from an upstream section of a coring bottom hole assembly (BHA), where the fluid has a first flow rate. The method can also include moving, based on the first flow rate of the fluid, a first flow regulating device within a cavity of a body of a subterranean coring assembly. The first flow regulating device can move to a first operating position within the cavity of the body when the first flow rate of the fluid is within a first range of flow rates. The first flow regulating device can move to a second operating position within the cavity of the body when the fluid has a second flow rate, where the second flow rate is within a second range of flow rates. The first operating position can correspond to a flushing mode of operation. The second operating position can correspond to a coring mode of operation. The second flow rate can exceed the first flow rate.

These and other aspects, objects, features, and embodiments will be apparent from the following description and the appended claims.

