Horizontal Wells 2019 Challenges and Opportunities

Technological techniques for conducting geophysical studies of existing horizontal wells, taking into account the geological field conditions of the field and tasks

The proposed algorithm for processing the azimuthal density image makes it possible to obtain more reliable information about the petrophysical properties of the reservoir and to clarify the effective thickness of the lithotypes crossed by a horizontal well. In relation to horizontal wells, a comprehensive analysis of well log data, the azimuthal density image, 3D seismic data and surface logging results makes it possible to more reliably determine the position of faults. The information obtained was used to adjust the well completion scheme, as a result of which a positive effect was obtained during hydraulic fracturing. The structural interpretation results clarified the fault and structural models.

The issues of well logging (in drilled and production horizontal wells) from the standpoint of their implementation in difficult conditions are considered. Proposed new technologies and special equipment to perform re-search in complex mining and geological conditions. The experience of the implementation of research by the Lateral technological complex of various modifications with different methods of stimulation of inflow is de-scribed. It is shown that the use of these technologies and special equipment allows to carry out research in hori-zontal wells with a full range of well logging and successfully achieve the goals.

In recent years many Russian oil companies in order to maintain stable production started to develop tight and particularly low permeability fields. Most of the tight fields in Russia were discovered in the 70s - 80s, but were not developed due to the presence of other more accessible and cheaper alternatives and also due to the lack of economically viable technologies. Improvement of technology of drilling horizontal wells with multistage hydraulic fracturing and tax incentives for tight field development allowed Russian oil companies to begin active development of the fields which were previously of no interest for economic reasons. Improving the construction of horizontal wells with multistage fracturing and the introduction of tax incentives for the development of hard-to-recovery fields allowed Russian oil companies to begin active development of fields that had not previously been of interest for economic reasons. The example of Achimov formation development shows solutions to optimize the development, which allowed to move from drilling horizontal wells of small length with multiple hydraulic fracturing to wells with a longer horizontal section with significantly reducing the number of wells. Technical difficulties that were solved for successful drilling and completion of elongated wells under HPHT conditions were discussed.

The presented novel approaches for oil and gas rims development enable the increase in hydrocarbon extraction using multilateral horizontal wells. Based on 3D static modelling results, it became possible to trace multilateral well trajectories of several types, which can enable much higher oil recovery efficiency. The important point was implementing appropriate well completion selection, which will increase the production efficiency by alignment of the inflow profile along a wellbore and isolation of undesirable water breakthrough intervals. The correct choice of inflow control devices (ICD) allows to get more uniform recovery of reserves. The proposed well completion design workflow is flexible to variable geological and technological factors and allows the ability to apply sophisticated well construction. Additional installation of the sliding sleeve for multiple hydraulic fracturing ports enables to make either acid fracturing (for carbonates) or proppant fracturing (for clastics) separately in any chosen interval. The comparative analysis of well performance showed that the performance of the designed horizontal wells in term of cumulative oil recovery is much higher versus conventional vertical wells. This enables the development of a deposit by less number of wells and ensures its economical efficiency, even despite of higher horizontal well price.

The paper presents the experience of Gazpromneft in the interpretation of well testing (hydrodynamic studies of wells) of horizontal wells, horizontal wells with multi-stage hydraulic fracturing.