Determination of the dispersed phase of polymer based drilling fluids

The purpose of the article is determination of the volume of the polymer solution dispersed phase, estimation of their subordination degree to the power law of fluid flow, as well as determination of the rheological model of mud flow in order to calculate the pressure losses under fluid movement in the elements of the circulation system. Water-soluble polymers are widely used in the composition of drilling fluids and are also used independently as flushing fluids for drilling wells. Despite the wide application range of polymers, when drilling little attention is paid to the volume of the dispersed phase resulting from the dissolution of polymer in water. Particular interest is caused by so-called dilute solutions (term used in the theory of polymer solutions). They are little mentioned in drilling but their number of macromolecular coils of the polymer reaches such a value that they do not interact with each other when the fluid flows. Using a viscometric method, the molecular mass and the characteristic viscosity of each solution used for the dispersion phase volume determination are estimated. The parameters of the rheological power law are determined through the application of rotametric viscometry. As a result, it has been found out that the solutions of the considered polymers prepared for the study are referred to diluted. On example of one of them the possibility of determining the relative volume of macromolecular coils of polymer with the immobilized solvent (water) is shown. It is demonstrated that a change in the specified volume causes a change in the parameters of the rheological power law of researched solution flow. The proposed methods for determining the relative volume of the dispersed phase of drilling muds based on dilute polymer solutions allows to adjust the rheological properties of flushing fluids and set the parameters of the rheological power law describing the flow of pseudoplastic fluids.

drilling mud, fluid viscosity, molecular weight, disperse phase, rheological law

1. Ovchinnikov V.P., Aksenova N.A., Kamenskii L.A., Fedorovskaya V.A. Polymer drilling muds. Their evolution "from rags to riches". Burenie i neft' [Oil and Drilling], 2014, no. 12, pp. 24–30. (In Russ.).

2. Kargin V.A. Entsiklopediya polimerov [Encyclopedia of polymers]. Moscow: Sovetskaya entsiklopediya Publ., 1972. Vol. 1, 323 р. (In Russ.).

3. Averkina E.V., Anisimov N.V., Trenev I.S. Issledovanie svoistv glinistykh burovykh rastvorov, obrabotannykh akrilovymi polimerami [Research of properties of the clay drilling muds processed by acrylic polymers]. Materialy Vseros. nauch.-tekhn. konf. s mezhdunar. uch., posvyashch. pamyati professora V.D. Matsa “Geonauki-2018: aktual'nye problemy izucheniya nedr” “Geologiya, poiski i razvedka poleznykh iskopaemykh i metody geologicheskikh issledovanii” [Materials of All-Russian scientific and technical conference with international participation devoted to the memory of the Professor V.D. Matz "Geosciences-2018: current problems of subsoil studies" “Geology, Search and Exploration of Minerals and Methods of Geologic Researches”. Irkutsk, 2018. Iss. 18, рр. 132–137. (In Russ.).

4. Lambin A.I., Ivanishin V.M., Siraev R.U., Averkina E.V., Shakirova E.V., Korotkov A.V. Study of the effect of emulsion drilling muds composition on their indicators. Izvestiya Sibirskogo otdeleniya Sektsii nauk o Zemle Rossiiskoi akademii estestvennykh nauk. Geologiya, poiski i razvedka rudnykh mestorozhdenii [Proceedings of the Siberian Department of the Section of Earth Sciences, Russian Academy of Natural Sciences. Geology, Prospecting and Exploration of Ore Deposits], 2015, no. 4 (53), рр. 58–66. (In Russ.).

5. Manzhai V.N., Klimova N.L. New opportunities of turbo-rheometric investigation method of polymer diluted solutions. Izvestiya Tomskogo politekhnicheskogo universiteta [Bulletin of the Tomsk Polytechnic University], 2006, vol. 309, no. 6, рр. 85–87. (In Russ.).

6. Shakirova E.V., Averkina E.V., Sabirov T.R. The effect of lubricating additives on characteristics of the mud used in well-drilling in Eastern Siberia. Izvestiya Sibirskogo otdeleniya Sektsii nauk o Zemle Rossiiskoi akademii estestvennykh nauk [Proceedings of the Siberian Department of the Section of Earth Sciences, Russian Academy of Natural Sciences. Geology, Prospecting and Exploration of Ore Deposits], 2016, no. 3 (56), рр. 86–94. (In Russ.). DOI: 10.21285/0130-108Х-2016-56-3-86-94.

7. Rabia H. Oil well drilling engineering, 1989, 413 p. (Russ. ed.: Rabia Kh. Tekhnologiya bureniya neftyanykh skvazhin. Moscow: Nedra Publ., 413 p.).

8. Reologicheskie modeli [Rheological models]. FluidsPro. URL: http://fluidspro.ru/reologiya-igidrodinamika/reologicheskie-modeli/ (accessed 22 November 2018).

9. Averkina E.V., Shakirova E.V., Sabirov T.R., Peryshkina K.O. Use of oil as lubricant additive in drilling mud fluid (on the example of the Yaraktinsky oil-gas condensate field). Neftegazovoe delo [Petroleum Engineering], 2018, vol. 16, no. 2, рр. 12–19. (In Russ.).

10. API RP 13D:1995. Recommended practice on the rheology and hydraulics of oil-well drilling fluids. American Petroleum Institute, 1220 L Street NW, Washington, DC 20005.