A COMPREHENSIVE METHODOLOGY FOR EVALUATING THE EFFECTIVENESS OF CHEMICAL INHIBITORS OF OPERATIONAL COMPLICATIONS IN OIL WELLS

Abstract

Abstract. The article addresses key challenges in oil well operation associated with the formation of asphaltene–resin–paraffin deposits, scale formation, corrosion, and other complicating factors characteristic of mature oil fields in Kazakhstan. It is shown that chemical inhibition is one of the most universal and technologically effective methods for protecting oilfield equipment at all stages of well production flow, from the near-wellbore zone to surface oil treatment facilities.

Particular attention is paid to the development and application of a comprehensive methodology for evaluating the effectiveness of paraffin deposit inhibitors. The methodology is based on a combination of differential scanning calorimetry (DSC), cross-polarized microscopy (CPM), and analysis of crude oil pour point, enabling an integrated investigation of both thermodynamic and morphological aspects of paraffin precipitation. Experimental studies were carried out on crude oil samples of different origins using commercial inhibitors over a wide range of concentrations.

The results demonstrated that changes in wax appearance temperature (WAT) are not always a sufficient criterion for assessing inhibitor performance. It was found that some reagents have a negligible effect on WAT while significantly altering the morphology and size of paraffin crystals, which directly affects the rheological properties of crude oil and its tendency to form deposits. The most effective inhibitor exhibited the ability to reduce the pour point of crude oil and transform the needle-like structure of paraffin crystals into agglomerated particles dispersed within the oil matrix.

It is shown that the combined analysis of DSC and CPM data allows for a more accurate evaluation of chemical inhibitor performance and a well-grounded selection of optimal reagents for operating wells with production complications. The obtained results confirm the feasibility of applying a comprehensive experimental approach in the development and implementation of inhibition programs aimed at improving equipment reliability, reducing operating costs, and ensuring sustainable hydrocarbon production in mature oil fields.