Influence of drilling fluids on the filtration properties of reservoirs

Abstract

Currently, during the opening and testing of productive formations, as well as during repair work in wells, specialized water- or oil-based technical fluids are used. All of them are characterized by compatibility to varying degrees with the lithological and physical properties of reservoirs in Western Siberia and have different effects on the filtration properties of the porous reservoir of productive formations. It is known that when using fresh water-based drilling fluids, due to the interaction of the fresh water filtrate with rock cement and some rock-forming minerals, the permeability of the bottom-hole zone changes. The paper presents the results of an experimental study of the effect of drilling fluids on terrigenous rocks of one of the fields. The impact of drilling fluids on the core, with the exception of FLO-PRO and NaCl, led to a decrease in the oil-permeability of core samples. In the core of the terrigenous reservoir, filtering FLO-PRO does not cause a negative result. The curves of permeability changes with increasing filtration pressure before and after FLO-PRO flow are identical in dynamics. According to the results of the study, it can be concluded that technical fluids FLO-PRO and IES (invert emulsion solutions) can be recommended for use as they do not violate the structure of the pore space of the reservoir and do not lead to a significant decrease in oil-permeability of all core layers.

Enhancing the quality of the initial discovery of carbonate gas deposits in the Zahoryanska field zone by improving the drilling mud

“…Drilling muds play an important role in ensuring the growth of drilling volumes and hydrocarbon production. Contamination of the bottomhole formation zone of the formation during primary and secondary opening and the associated deterioration of natural reservoir properties can lead to a significant loss of well productivity and, conversely, minimization of such contamination can allow obtaining industrial products from deposits, the production of which, even recently, was impossible for technical or economic reasons [5][6][7][8][9].…”

“…The drilling of oil and gas wells leads to a destruction of the natural balance of fluid saturation of productive layers. As a result of the penetration of leachate and the solid phase of washing or process fluids, the character of the saturation of the pore space of the rocks in the bottomhole formation zone of the formation changes, processes occur that are caused by the physical and chemical interaction of drilling muds with the rock and formation fluids, which significantly worsen the filtration properties of the rocks [5].…”

“…The influence of flushing fluids on productive formations is due to penetration into the pore space of the filtrate collector and dispersed phase, swelling of clay cement, formation of solid sediments and emulsions during interaction with formation fluids, reduction of effective pore volume [5,6]. All this leads to deterioration of productive characteristics of wells.…”

Field and Experimental Investigations on the Effect of Reservoir Drill-In Fluids on Penetration Rate and Drilling Cost in Horizontal Wells

“…Developments in science and technology, especially over the last two decades, have led to the production of several synthetic polymers worldwide that have resistance to higher Gels 2023, 9, 510 2 of 17 temperatures, such as FLOTROL polymers that are used to make up FLOPRO drilling fluid. FLOTROL polymers are more stable at higher temperatures, with less chemical concentration, non-formation damage, zero non-productive time for drilling fluid, and the ability to drill more than 2000 m horizontally at a cost that is significantly lower than commercial polymers [15,16].…”