The objective of this study is to evaluate the role of nanoparticles with different chemical structures in completion fluids (CF) in providing a positive dual effect for well stimulation and clay swelling damage inhibition. Six types of commercial (C) or synthesized (S) nanoparticles have been incorporated into a commercial completion fluid. Doses varied between 100 and 500 mg·L−1. CF-nanoparticles were evaluated by fluid–fluid, fluid–nanoparticle, and fluid–rock interactions. The adsorption isotherms show different degrees of affinity, which impacts on the reduction of the interfacial tension between the CF and the reservoir fluids. Fluid–fluid interactions based on interfacial tension (IFT) measurements suggest that positively charged nanoparticles exhibit high IFT reductions. Based on contact angle measurements, fluid–rock interactions suggest that ZnO-S, SiO2-C, SiO2-S, and ZrO2 can adequately promote water–wet rock surfaces compared with other nanomaterials. According to the capillary number, ZnO-S and MgO-S have a higher capacity to reduce both interfacial and surface restrictions for crude oil production, suggesting that completion fluid with nanoparticles (NanoCF) can function as a stimulation agent. The clay swelling inhibition test in the presence of ZnO-S-CTAB and MgO-S-CTAB nanoparticles showed a 28.6% decrease in plastic viscosity (PV), indicating a reduction in clay swelling. The results indicate that a high-clay environment can meet the completion fluid’s requirements. They also indicate that the degree of clay swelling inhibition of the nanoparticles depends on their chemical nature and dosage. Finally, displacement tests revealed that CF with nanoparticles increased the oil linear displacement efficiency.

The objective of this research was to develop and incorporate nanodetectors (NDs) in drilling fluids to identify the contribution of the different producing zones in naturally fractured carbonate reservoirs. The NDs were designed to interact with the crude oil and release the active compound that allows for fluorescence emission for surface detection. Novel nanocapsules based on carbon quantum dots (CQDs) were synthesized using various nanomaterials as the core and soy lecithin as the shell. Four CQDs were used: CQD green, CQD light blue, CQD red, and CQD dark blue. CQD red was discarded as a result of high retention in calcium carbonate, and encapsulation was performed with the others to form ND1, ND2, and ND4, respectively. The technology was assured through compatibility tests with reservoir fluids, static efficiency tests, and static retention. NDs had sizes smaller than 75 nm. Also, solubility tests showed that the active compound was released upon contact with oil-based systems. The characterization of the drilling fluids indicated that properties, such as the yield point and plastic viscosity, remained the same in the presence of the ND, which allows for its use under field conditions and secure wellbore stability. The technology was successfully implemented in a Colombian oil field. Filed results showed correlations between the gas profiles, brittleness of the zone, open fractures, and concentration of nanodetectors, which allows for the conclusion of the effectiveness of the nanostructures for the detection of naturally fractured zones of the evaluated wells.