Selection of the optimal composition of the killing fluid for the conditions of the field N and determination of scaling conditions in process of well intervention

UDK: 622.276.76

DOI: 10.24887/0028-2448-2025-6-60-64

Key words: tight reservoirs, well testing, selection of well killing fluids, temporary blocking agents (pills)

Authors: T.S. Rogova (ZN NTC LLC, RF, Moscow); Y.V. Lobova (ZN NTC LLC, RF, Moscow); A.S. Levchenko (ZN NTC LLC, RF, Moscow); E.P. Panarina (ZN NTC LLC, RF, Moscow); A.V. Kornilov (ZN NTC LLC, RF, Moscow); Y.M. Trushin (ZARUBEZHNEFT-Dobycha Kharyaga LLC, RF, Moscow); I.A. Krasnov (ZARUBEZHNEFT-Dobycha Kharyaga LLC, RF, Moscow)

The article observes a problem of reduced well productivity index for field N for which a multistage hydraulic fracturing technology is used. Results of well testing and performance analysis showed that the reason of this effect is impaired connectivity between the well and the formation. Several reasons were considered as a part of productivity decline, one of them is scale deposition CaCO3 in process of chemical reaction between killing fluid CaCl2 used in completion process and formation water, later this hypothesis was confirmed by the results of electrical submersible pump dismounting. As a solution for the problem the authors considered optimization of killing fluid composition or use of temporary blocking agents (pills) to reduce the contact of completion fluid with formation water. As a result of physical-chemical and filtration tests, several compositions and blocking agents stable at formation temperature up to 120 °C were selected, aiming to reduce the risks in future well interventions in the field. As additives to killing fluids, it is recommended to use polymer chemicals that increase the viscosity of solutions and reduce water loss, surfactants to compensate for the negative impact of the killing fluid on the formation, and flow assurance chemicals (in particular, corrosion and scale inhibitors).

References

1. Kremenetskiy M.I., Ipatov A.I., Primenenie promyslovo-geofizicheskogo kontrolya dlya optimizatsii razrabotki mestorozhdeniy nefti i gaza (Application of field geophysical control to optimize the development of oil and gas fields), Part I. Osnovy gidrodinamiko-geofizicheskogo kontrolya razrabotki i monitoringa dobychi (Fundamentals of hydrodynamic-geophysical control of development and production monitoring), Moscow - Izhevsk: Publ. of Institute of Computer Science, 2020, 676 p.

2. Kolesnikov M.V., Panarina E.P., Kremenetskiy M.I., Pakhomov E.S., The possibilities of field geophysical surveys for the diagnosis of horizontal wells with different types of completion (In Russ.), Aktual'nye problemy nefti i gaza, 2024, V. 15, no. 3, pp. 296–311, DOI: https://doi.org/10.29222/ipng.2078-5712.2024-15-3.art7

3. Ryabokon' S.A., Tekhnologicheskie zhidkosti dlya zakanchivaniya i remonta skvazhin (Process fluids for completion and repair of wells), Krasnodar, 2016, 382 p.

4. Caenn R., Darley H.C., Gray G., Composition and properties of drilling and completion fluids, Amsterdam: Gulf professional publishing, 2011, 720 p.,

DOI: https://doi.org/10.1016/C2009-0-64504-9

5. RD 39-2-645-81. Metodika kontrolya parametrov burovykh rastvorov (Methodology for monitoring parameters of drilling fluids), Krasnodar: VNIIKRneft', 1981.