Real-time method for maintaining formation stability and monitoring fluid-formation interaction

A method for servicing a wellbore penetrating a subterranean formation using well service fluid, said method comprising real-time monitoring of the stability of said wellbore using a wellbore stability model said method further comprising:

• obtaining a preliminary value for weight or one or more chemical properties of said well service fluid using said wellbore stability model;
• measuring transient pressure response of the formation and at least one of the formation characteristics selected from the group consisting of acoustic, electrical, thermal and density characteristics;
• calibrating said wellbore stability model with said measurements;
• and
• obtaining a value for the weight or a chemical property of said well service fluid using said calibrated wellbore stability model.

A method for maintaining stability of a wellbore penetrating a subterranean formation during drilling or well servicing operations, or during production or enhanced recovery operations, using fluid introduced into said wellbore to facilitate said operations, said method comprising:

• estimating characteristic properties of the formation;
• estimating in-situ stresses in the formation;
• estimating or determining characteristic properties of said fluids;
• estimating the rock strength of said formation;
• conducting at least one pore pressure versus time laboratory test based on said estimations of fluid properties, formation properties, and rock strength;
• employing results of said test, said estimations of formation properties, in-situ stresses, rock strength, and said fluid properties in a wellbore stability model;
• using results from said model to adjust estimates of said formation properties, in-situ stresses in the formation;
• and rock strength to update said wellbore stability model or using results from said model to adjust the properties of said fluid to maintain or enhance said rock strength;
• continuing during said operations to estimate or measure characteristic properties of the formation and of said fluid during said well operations and continuing to repeat or update on a real-time basis the estimates of in-situ stresses and rock strength based on said properties, wherein said characteristic properties of the formation which are measured during said wellbore operations comprise at least one of the formation characteristics selected from the group consisting of acoustic, electrical, thermal, density, and transient pressure responses of the formation;
• and
• continuing to update the wellbore stability model and continuing to adjust on a real-time basis the properties of said fluid as needed to maintain or enhance said rock strength during said operation.

A method employing drilling fluid for drilling a wellbore penetrating a subterranean formation, said method comprising real-time monitoring of the stability of said wellbore using a wellbore stability model, and said method further comprising:

• (a) obtaining a preliminary value for the weight of said drilling fluid using said wellbore stability model;
• (b) measuring at least two of the formation characteristics selected from the group consisting of acoustic, electrical, thermal, density, and transient pressure responses of the formation;
• (c) calibrating said wellbore stability model with said measurements;
• and
• (d) obtaining a value for the weight of said drilling fluid using said calibrated wellbore stability model.

A method employing well service fluid for servicing a wellbore penetrating a subterranean formation, said method comprising real-time monitoring of the stability of said wellbore using a wellbore stability model during said servicing of said wellbore, said method further comprising:

• obtaining a preliminary value for the weight of said well service fluid using said wellbore stability model;
• measuring at least two of the formation characteristics selected from the group consisting of acoustic, electrical, thermal, density, and transient pressure responses of the formation;
• calibrating said wellbore stability model with said measurements;
• and
• obtaining a value for the weight of said well service fluid using said calibrated wellbore stability model.

A method for real-time monitoring the stability of a wellbore drilled with a drilling fluid using a wellbore stability model, said method comprising the steps of:

• (a) obtaining a preliminary value for one or more chemical properties of said drilling fluid using said wellbore stability model;
• (b) measuring at least two of the formation characteristics selected from the group consisting of acoustic, electrical, thermal, density, and transient pressure responses of the formation;
• (c) calibrating said wellbore stability model with said measurements;
• and
• (d) obtaining a value for said one or more chemical properties of said drilling fluid using said calibrated wellbore stability model.

A method employing well service fluid for servicing a wellbore penetrating a subterranean formation, said method comprising real-time monitoring of the stability of said wellbore using a wellbore stability model during said servicing of said wellbore, said method further comprising:

• obtaining a preliminary value for one or more chemical properties of said well service fluid using said wellbore stability model;
• measuring at least two of the formation characteristics selected from the group consisting of acoustic, electrical, thermal, density, and transient pressure responses of the formation;
• calibrating said wellbore stability model with said measurements;
• and
• obtaining a value for one or more of the chemical properties of said well service fluid using said calibrated wellbore stability model.