System and method for methane hydrate based production prediction
AssigneeSchlumberger Technology Corporation
InventorsBei Gao, Yen Han Shim, Li Chen, Jichao Chen, Wei Zhang, Huimin Cai, Chang Wei Qu
Life of this patent
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Abstract
This disclosure relates to techniques for determining a dissociation constant of a reservoir that includes methane hydrate and generating a methane hydrate production output that may be used to inform certain decisions related to processing a reservoir that includes the methane hydrate. In some embodiments, the techniques may include determining the dissociation constant using multiple pressures measured at different flowrates at time points from within a wellbore.
Claims20
A method, comprising:
- receiving a flow of a formation fluid into a downhole tool, wherein the formation fluid comprises methane hydrate from a geological formation;
- measuring one or more flow properties of the formation fluid using the received flow of the formation fluid;
- determining a dissociation constant of the methane hydrate based at least in part on:
- a quotient of a change in concentration of the methane hydrate over time divided by a product of a contact area between the downhole tool and the geological formation and one or more measured flow properties of the formation fluid, wherein the change in concentration of the methane hydrate over time is determined based on:
- a mass of methane hydrate defined according to a product of a gas fraction associated with the formation fluid, a density of methane, and a flow rate of the formation fluid;
- modifying a drawdown pressure based on the dissociation constant;
- and
- generating a methane hydrate production output based on the dissociation constant of the methane hydrate.
A tangible, non-transitory, computer-readable medium, comprising computer-readable instructions that, when executed by one or more processors, cause the one or more processors to:
- receive one or more measured flow properties of a formation fluid associated with a reservoir within a geological formation, wherein the formation fluid comprises methane hydrate;
- determining a dissociation constant of the methane hydrate based at least in part on:
- a quotient of a change in concentration of the methane hydrate over time divided by a product of a contact area between a downhole tool and the geological formation and the one or more measured flow properties of the formation fluid, wherein the change in concentration of the methane hydrate over time is determined based on:
- a mass of methane hydrate defined according to a product of a gas fraction associated with the formation fluid, a density of methane, and a flow rate of the formation fluid;
- modifying a drawdown pressure based on the dissociation constant;
- and
- determining a methane hydrate production output based at least in part on the dissociation constant.
A system, comprising:
- a downhole tool configured to receive a flow of a formation fluid from a reservoir within a geological formation;
- and
- a data processing system communicatively coupled to the downhole tool, wherein the data processing system is configured to:
- receive a first measurement indicative of a flowing pressure of the formation fluid into the downhole tool, wherein the formation fluid comprises methane hydrate;
- receive a second measurement indicative of an equilibrium pressure of the formation fluid;
- determine a dissociation constant associated with the methane hydrate based on;
- a quotient of a change in concentration of the methane hydrate over time divided by a product of a contact area between the downhole tool and the geological formation and the flowing pressure, the equilibrium pressure, or both, wherein the change in concentration of the methane hydrate over time is determined based on:
- a mass of methane hydrate defined according to a product of a gas fraction associated with the formation fluid, a density of methane, and a flow rate of the formation fluid;
- modify a drawdown pressure based on the dissociation constant;
- and
- generate a methane hydrate production output based at least in part on the dissociation constant.
Dependencies are inferred from the claim text.