Abstract: A method for determining whether crude oil has been produced from a hydrocarbon reservoir wellbore that has been drilled using an oil-based mud (OBM). The method includes proving the OBM which contains a tracer, filtering the OBM to obtain an OBM filtrate comprising the tracer, determining a baseline absorbance value for the OBM filtrate containing the tracer, determining a baseline absorbance value for the crude oil, introducing the OBM filtrate into a hydrocarbon reservoir wellbore, conducting a wellbore operation with the OBM, producing a sample from the well, measuring a measured absorbance value for the sample, and comparing the measured absorbance value with the baseline absorbance values for the OBM filtrate and the baseline absorbance value for the crude oil to determine whether crude oil is present in the sample.

Abstract: A method includes disposing a device into a borehole in proximity to a subterranean formation where a filter cake has been formed adjacent thereto, the device comprising a support structure and a shape-memory article disposed at the support structure, the shape-memory article comprising a shape-memory polymer, wherein the device is disposed when the shape-memory article is in a compacted shape; exposing the shape-memory article to a fluid system to cause the shape-memory article to expand and conform to a surface of the borehole; exposing the filter cake to the fluid system; and removing the filter cake with the fluid system. The fluid system comprises a chelating agent, an activator, a non-emulsifier, and water or a brine.

Abstract: A method includes disposing a device into a borehole in proximity to a subterranean formation where a filter cake has been formed adjacent thereto, the device comprising a support structure and a shape-memory article disposed at the support structure, the shape-memory article comprising a shape-memory polymer, wherein the device is disposed when the shape-memory article is in a compacted shape; exposing the shape-memory article to a fluid system to cause the shape-memory article to expand and conform to a surface of the borehole; exposing the filter cake to the fluid system; and removing the filter cake with the fluid system. The fluid system comprises a chelating agent, an activator, a non-emulsifier, and water or a brine.

Abstract: A method for improving mobility of heavy crude oil in a subterranean reservoir is provided. A fluid formulation can be introduced into the reservoir, the fluid formulation comprising water and a surfactant, and optional co-solvents. The fluid formulation can produce one or more of a dispersion and an emulsion in the reservoir, whereby the surfactant acts as an dispersant or emulsifying agent, emulsifier and/or drag reducing agent. The emulsion or the dispersion can have a water external phase and a crude oil internal phase.

Abstract: A method for improving mobility of heavy crude oil in a subterranean reservoir is provided. A fluid formulation can be introduced into the reservoir, the fluid formulation comprising water and a surfactant, and optional co-solvents. The fluid formulation can produce one or more of a dispersion and an emulsion in the reservoir, whereby the surfactant acts as an dispersant or emulsifying agent, emulsifier and/or drag reducing agent. The emulsion or the dispersion can have a water external phase and a crude oil internal phase.