Method for in situ fluid assessment and optimization during wellbore displacement operations

Abstract

The present invention is, in some embodiments directed to methods for optimizing wellbore displacement operations via in situ fluid property assessment / monitoring. By monitoring fluid properties in situ (i.e., downhole), fluid property assessment is direct instead of being inferred. Additionally, wherein such assessment / monitoring is carried out in real time, changes to the displacement fluid can be made “on-the-fly,” thereby contributing to an enhancement of the overall efficiency of the method.

Description

FIELD OF THE INVENTION[0001]This invention relates generally to wellbore completion operations, and specifically to methods for assessing and / or optimizing wellbore fluid displacement operations.BACKGROUND[0002]Numerous situations and / or scenarios exist in which wells are extended to subterranean locations in the earth's crust. For example, wells are drilled into subterranean / geologic formations in order to provide for the production of a variety of fluids, such as water, gas and / or oil; or for the injection of fluids, such as is employed in the secondary and tertiary recovery of oil (e.g., enhanced oil recovery). In many such situations and / or scenarios, in order to properly support the wall of the well, and possibly to exclude fluids from undesirably traversing the boundaries of at least some portions of the well, the well is cased with one or more strings of pipe, i.e., casing strings.[0003]In order to complete the well, the casing must be bonded to the formation using a cementin...

AI Technical Summary

Benefits of technology

[0007]The present invention is generally directed to methods for optimizing wellbore displacement operations via in situ fluid property assessment / monitoring, thereby providing direct assessment of one or more properties of one or more fluids under the environmental conditions to which that fluid(s) experience in the well. In some embodiments, such in situ fluid property assessment / monitoring is performed in real time. By monitoring fluid properties in situ (i.e., downhole), fluid property assessment can be direct, as opposed to being inferred (as in the prior art). Additionally, changes to the displacement fluid can be made “on-the-fly,” thereby contributing to an enhancement of the overall efficiency in terms of time savings and reduced fluid waste.

[0008]In some embodiments, the present invention is directed to one or more methods for optimizing wellbore displacement operations, such methods comprising the steps of: (a) introducing a quantity of spacer fluid into a well via a workstring, said well initially occupied by a solids-laden working fluid, the spacer fluid establishing a first interface between it and the solids-laden working fluid; (b) following the spacer fluid introduction with a completion fluid, a second interface being established between the completion fluid and the spacer fluid; (c) monitoring, in situ, at least one fluid selected from the group consisting of working fluid, spacer fluid, and completion fluid, as said fluid is displaced up the annular region of the well; wherein such monitoring provides an in situ fluid property assessment of at least one fluid property (e.g., turbidity, density, solids concentration, capacitance, viscosity, resistivity, temperature, pressure, radioactivity, salinity, basic sediment and water (BS&W), and the like); and (d) communicating the in situ fluid property assessment uphole for purposes of optimizing wellbore displacement operations. In some such method embodiments, there may further comprise a step (e) of facilitating optimization of wellbore displacement operations via the real-time assessment of fluid properties communicated in step (d).

[0009]In some or other embodiments, the present invention is directed to one or more methods for in situ downhole monitoring of fluids in a well during fluid displacement operations, said well being operable for producing hydrocarbons, and said method comprising the steps of: (a′) introducing a quantity of spacer fluid into a well via a workstring, said well initially occupied by a solids-laden working fluid, the spacer fluid establishing a first interface between it and the solids-laden working fluid, wherein the solids laden working fluid is selected from the group consisting of drilling fluids, workover fluids, brine systems, and combinations thereof; (b′) following the spacer fluid introduction with a completion fluid, a second interface being established between the completion fluid and the spacer fluid; (c′) monitoring, in situ, at least one fluid selected from the group consisting of working fluid, spacer fluid, and completion fluid, as said fluid is displaced up the annular region of the well; wherein such monitoring provides an in situ fluid property assessment of at least one fluid property selected from the group consisting of turbidity, density, solids concentration, capacitance, viscosity, resistivity, temperature, pressure, radioactivity, salinity, basic sediment and water (BS&W), and combinations thereof); (d′) wirelessly-communicating the in situ fluid property assessment uphole, wherein such wireless communication is of a form selected from the group consisting of pressure pulses, acoustic transmissions, electromagnetic transmissions, and combinations thereof; and (e′) facilitating optimization of wellbore displacement operations, wherein optimization is afforded by real time assessment of fluid properties in situ.

Problems solved by technology

However, because completion fluids are typically incompatible (for a variety of reasons) with drilling fluids, the completion fluid can be preceded by a spacer fluid during a displacement operation.

Images