Controle fuzzy multivariável para correção de propriedades físico-químicas de fluidos de perfuração
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| Utgivningsdatum: | 2024 |
| Materialtyp: | Master thesis |
| Språk: | por |
| Källa: | Repositório Comum do Brasil - Deposita |
| Download full: | https://deposita.ibict.br/handle/deposita/772 |
Sammanfattning: | In oil activities, during the drilling stage, the use of drilling fluids becomes essential for the success of the entire operation. These drilling fluids are constituted by adding chemical products to a base fluid, which can be classified according to the type of base fluid used in their formulation, categorized as water-based, oil-based, or gas-based fluids. These fluids exert numerous properties, but those related to rheological properties and maintaining the hydrostatic pressure gradient within the well are particularly noteworthy. Considering that drilling fluids are subject to fluid-rock interactions, contamination by salts from the geological formation can become a problem during the well exploration stage, potentially impacting the rheological characteristics and density of the fluid. An increase in the electrical conductivity of the fluid indicates the increase in salt presence in waterbased drilling fluids. However, the monitoring and control of this property have yet to be explored so far. This work proposed developing a multivariable fuzzy control system for correcting water-based drilling fluids' electrical conductivity, density, and apparent viscosity. The developed control technique was evaluated through an experimental unit for the preparation and monitoring of drilling fluids equipped with mixing and water storage tanks, a helical pump for fluid recirculation, a water dosing pump, and solid feeders. The unit's instrumentation includes sensors for measuring conductivity, temperature, level, flow rate, density, and apparent viscosity. The data acquisition system of the experimental unit consists of a National Instruments PLC using LabVIEW® supervisory software. The fuzzy control strategy was developed using the LabVIEW® software. For the performance evaluation of the controller, servo and regulatory control problems involving the properties of electrical conductivity, apparent viscosity, and density were proposed. Experimental tests were also conducted to evaluate the interaction between the fluid composition and the controlled variables. In bench experimental tests, it was observed that the evaluated properties have statistically significant interactions with each other. However, the increase in sodium chloride concentration does not alter the pseudoplasticity of the fluids. Regarding the performance of the fuzzy controller, the results demonstrated the effectiveness of the proposed strategy in maintaining the electrical conductivity, apparent viscosity, and density of the fluids, thus evidencing its potential use as a tool for multivariable control of the physical properties in drilling fluids. It was also possible to identify that electrical conductivity was the most sensitive variable in relation to density and apparent viscosity. |