The experience of successful well completion in the Verkhnomaslovetsk field of PJSC «Ukrnafta»

Abstract

The mining and geological features of the wells construction at the unique Verkhnomaslovetsk field of PJSC «Ukrnafta» were characterized. The main technical and technological incidents, their causes and methods of
elimination are considered. It is shown that the biggest problem is the violation of the integrity of the walls of the well and the intensive absorption of technological fluids due to geological features of the Boryslav Sandstone. The experience of successful implementation of the project is shown on the example of well No 103, in particular, wellbore trajectory, the conditions of selection and application for the successful primary disclosure of productive
horizons. The challenges and solutions regarding the fastening of the well with the production column are shown. Emphasis is placed on the efficiency of using innovative composite, domestic tamponage systems. The processes of structure formation of such materials can be controlled by the use of modern materials of modifiers, in particular krents, the use of which is potentially able to ensure the controlled growth of reinforcing crystals, providing a kind of synthesis of the stone during its hardening and creating the prerequisites for «self-healing» of the broken
structure. In particular, designed taking into account the innovative principle of "tandem technologies", stabilized tamping mixtures with an expanding effect YNG-Cem-EA50-LF, YNG-Cem-EALW-LF and stabilized buffer mixture with increased washing and separating properties YNG-Cem-DSM, were used for cementing the production column. These materials are characterized by high stability, minimal filtration performance, as well as controllability of the surface tension of the dispersion medium filtrate, which practically eliminates the potentially negative impact of fastening on the collector properties of productive layers. The technological features of the successful application of the specified materials in difficult mining and geological conditions under the risks of absorption are considered. The results make it possible to optimize further work on this field and the fields with similar mining and geological conditions.