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.

1 . A method for in situ downhole monitoring of fluids in a well during fluid displacement operations, 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;   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; and   d) communicating the in situ fluid property assessment uphole for purposes of facilitating wellbore displacement operations.   
     
     
         2 . The method of  claim 1 , wherein the well is operable for producing hydrocarbons, wherein said hydrocarbons are selected from the group consisting of oil, gas, and combinations thereof, and wherein the well is selected from the group consisting of a land-based well and an offshore well. 
     
     
         3 . The method of  claim 1 , wherein the at least one fluid property is selected from the group consisting of turbidity, density, solids concentration, capacitance, viscosity, resistivity, temperature, pressure, radioactivity, salinity, basic sediment and water, and combinations thereof. 
     
     
         4 . The method of  claim 1 , wherein the solids laden working fluid is selected from the group consisting of drilling fluids, workover fluids, brine systems, and combinations thereof. 
     
     
         5 . The method of  claim 1 , wherein the spacer fluid is introduced as a pill. 
     
     
         6 . The method of  claim 5 , wherein the spacer fluid is introduced as a series of pills exhibiting a progressive variation in at least one property across the series. 
     
     
         7 . The method of  claim 5 , wherein the spacer fluid is compatible with both the solids-laden working fluid and the completion fluid. 
     
     
         8 . The method of  claim 1 , wherein said step of monitoring is carried out in a manner selected from the group consisting of continuous monitoring, discrete monitoring, and combinations thereof. 
     
     
         9 . The method of  claim 1 , wherein the step of monitoring requires a plurality of fluid property analyzers positioned in said well to monitor the at least one fluid. 
     
     
         10 . The method of  claim 9 , wherein at least some of the plurality of fluid property analyzers provide fluid assessment of different fluid properties. 
     
     
         11 . The method of  claim 9 , wherein the plurality of fluid property analyzers are positioned at different locations in the well, so as to monitor fluids at different points along the annular region of the well. 
     
     
         12 . The method of  claim 1 , wherein the step of communicating involves cabled communication of fluid property analyzer data. 
     
     
         13 . The method of  claim 1 , wherein the step of communicating involves wireless communication of fluid property analyzer data. 
     
     
         14 . The method of  claim 13 , wherein wireless communication is of a form selected from the group consisting of pressure pulses, acoustic transmissions, electromagnetic transmissions, and combinations thereof. 
     
     
         15 . The method of  claim 1 , further comprising a step of facilitating optimization of wellbore displacement operations, wherein optimization is afforded by real time assessment of fluid properties. 
     
     
         16 . A method 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 the like, 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.   
     
     
         17 . The method of  claim 16 , wherein the spacer fluid is introduced as a pill. 
     
     
         18 . The method of  claim 17 , wherein the spacer fluid is introduced as a series of pills exhibiting a progressive variation in at least one property across the series. 
     
     
         19 . The method of  claim 16 , wherein the step of monitoring requires a plurality of fluid property analyzers are positioned in said well to monitor the at least one fluid, and wherein at least some of the plurality of fluid property analyzers provide fluid assessment of different fluid properties. 
     
     
         20 . The method of  claim 19 , wherein the plurality of fluid property analyzers are positioned at different locations in the well, so as to monitor fluids at different points along the annular region of the well.