Reducing the negative impact of high density killing solutions on the productivity of gas wells operating achimov reservoirs. Part 1. Selection and modification of heavy killing fluids

DOI: 10.24412/2076-6785-2023-3-52-57

Abstract
The article deals with peculiarities and complications when killing gas wells in conditions of Achimovsky reservoirs (Ach3-4 and Ach52-3 formations of Novo-Urengoyskiy and Vostochno-Urengoyskiy license areas). In particular, there is intensive absorption of liquids, reduction of well productivity, corrosive effect on downhole equipment, and loss of stability in high temperature conditions. The dependence of the change in the skin factor on the density of the basic polymer-clay drilling mud used for killing the well has been determined. On the basis of the conducted complex of laboratory tests it was established that the modified high-density solutions on the basis of calcium chloride and calcium nitrate mixture (density 1 600 kg/m3) and zinc chloride and calcium bromide mixture (density 1 910 kg/m3) provide high recovery of formation model permeability after killing.

Materials and methods
Analysis of the results of application of killing technologies at the
Novo-Urengoyskiy and Vostochno-Urengoyskiy license areas. Substantiation of a choice of new technology on the basis of world experience and results of researches of basic applied fluids. Physical-chemical and filtration studies of high-density modified salt solutions in the conditions of the object in question.

Keywords
Urengoyskoe field, well killing, gas wells, abnormally high reservoir pressure, high temperature, fluid loss, blocking compounds, suspensions, modification