In case of abnormally high formation pressures well-killing is a set of measures for the selection, preparation and injection of heavy well-killing fluids into the well. It should be noted that industrial fluids are expensive and do not always meet the requirements for well killing fluids for the conditions of Subsidiaries of Gazprom Neft Company. In order to search for high-quality process fluids with a density of up to 1600 and 1800 kg/m3 for killing production and injection wells at the fields of Gazprom Neft, laboratory studies were carried out. For extensive market research, inquiries were formed and sent to the base of manufacturers from 150 companies. 38 ready-mades well-killing fluids with density up to 1600 and 1800 kg/m3 were received from manufacturers. An analysis of the compliance with the technical documentation was passed by all 38 reagents. When carrying out physical and chemical studies of samples the main inconsistencies were identified in the following parameters: increased corrosiveness and incompatibility with formation waters at high formation temperature (85-114°C), high total suspended solids. Manufacturers are offered to improve the presented fluids to meet the requirements of the standard. Two compositions are recommended for further filtration studies. During series of filtration experiments, it was found that the lower porous medium permeability and the greater the hydrophilicity of the rock, the lower the coefficient of permeability recovery after well-killing. A twofold increase in the filtration rate makes it possible to increase the permeability recovery factor up to 2.5 times, which indicates a trouble-free development of the well after killing with the tested compositions with an increase in drawdown. Only one product was met all requirements for heavy well-killing fluids and were recommended for use at 3 Company’s fields. Due to the non-compliance of most of the products of the external market with the requirements of the Company, a decision was made to develop own formulations of heavy well-killing fluids.
References
1. Patent RU 2 731 965 C1, Heavy process fluid for killing wells, composition and method for preparation thereof, Inventors: Karpov A.A., Kunakova A.M., Kaybyshev R.R., Puchina G.R., Sergeeva N.A., Ragulin V.V.
2. Ryabokon’ S.A., Tekhnologicheskie zhidkosti dlya zakanchivaniya i remonta skvazhin (Process fluids for completion and repair of wells), Krasnodar: Publ. of NPO Burenie, 2009, 337 p.
3. Kunakova A.M., Duryagin V.N., The improvement of economic efficiency of the well control process by the implementation of new process liquids (In Russ.), PROneft’.Professional’no o nefti, 2016, no. 2. pp. 61–63.
4. Khakimov A.M., Makatrov A.K., Karavaev A.D. et al., Filtration testing of a new generation of surfactants of domestic and foreign production as additives to repair and process fluids during underground repairs and BHT of wells in hydrophilic reservoirs (In Russ.), Neftepromyslovoe delo, 2005, no. 12, pp. 48–53.
5. Kunakova A.M., Karpov A.A., Makarova A.M., Development of new formulations of heavy well killing fluids with density of up to 1600 kg/m3 for the conditions of the fields of Gazprom Neft (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2021, no. 12, pp. 34-38, https://doi.org/10.24887/0028-2448-2021-12-34-38
