First Fishbone Well Drilling at Vankorskoe Field

Abstract

A horizontal well in Vankor oil field, Russia, was drilled with a multilateral fishbone shape to increase production. This type of drilling, in which branches (ribs) are drilled into a single layer from the main horizontal section, increases the reservoir drainage area over that covered by single-bore horizontal wells. In recent decades, rotary steerable systems (RSS) have been actively used by the Russian oil industry to drill elongated horizontal wells in sweet formation zones. This strategy is possible because of the development and availability of RSS technology in the oil and gas industry and is financially feasible because the production rate of horizontal wells is greater than that vertical wells. The Vankor is one of the largest oil fields in Russia. Since 2009, advanced RSS technologies have been successfully used in this field to develop reservoirs by drilling horizontal holes with length ranges from 300 to 1000m. One of the three major formations in this field is the Cretaceous Nizhnekhet 1 formation, with a thickness of approximately 1 to 2 meters. It is the thinnest reservoir formation in the field, and it exhibits the lowest recovery rate against the two other major reservoirs. The fishbone drilling strategy was adopted by the operator to improve the single-well production rate from the Nizhnekhet 1 formation. Given the geological conditions, the main significant challenge is to place ribs from the horizontal hole in a narrow drilling tunnel 1 m above and 1 m below the trajectory. In December, 2014 the first fishbone well in the Vankor field was drilled. The well plan called for drilling a multilateral well with nine additional branches from the main horizontal borehole. Technologies applied during drilling included control of the trajectory with geologically oriented drilling and openhole sidetracking. A multifunctional team of drilling engineers and geologists from the operator and the service company successfully placed the branches within the 2-m thick reservoir. In early production results, the fishbone well showed two times higher production compared to a single-bore horizontal well. Implementation of lessons learned from this first fishbone well in Vankor field will create new approach to multiplying the productivity of horizontal wells coming through involvement in the development of additional volumes of oil in rocks with low productivity and also, by increasing the area of interaction with the productive part of the reservoir within the same horizontal wells.

A Comprehensive Review of Fishbone Well Applications in Conventional and Renewable Energy Systems in the Path towards Net Zero

“…Various studies have shown the successful application of fishbone well designs in different regions and geological formations, including Russia's Vankorskoe Field [19], Abu Dhabi National Oil Company's (ADNOC) onshore field in a tight carbonate formation [20], Aasgard Field in Norway [21], and Vostochno-Messoyakskoye onshore field in Russia [22]. Productivity enhancements were also observed in the United Arab Emirates (UAE) with a 300% increase during the application of fishbone well technology in a very tight reservoir [23].…”

Introduction to Smart Oil and Gas Wells: Drilling, Completion and Monitoring Solutions

“…In the oil and gas service market, generally, there are many different available types of gauges. Two types are going to be clarified briefly in this research study; electrical and optical [13].…”

Design and Performance Analysis of Dry Gas Fishbone Wells for Lower Carbon Footprint

“…In Venezuela, the Zuata field, which comprises nonhomogeneous sand, has been documented as the first successful application of Fishbone design (FbD) [15]. The first FbD application in Russia was reported in the Nizhnekhet 1 field, a very thin formation [16]. Four additional case studies from Russia have been documented in the literature, including sandstone formations in the Vostochno-Messoyakskoye onshore field [17], low permeable formations in the East Messoyakha field [18], the Vankor oilfield in Krasnoyarsk, Eastern Siberia [19], and the Srednebotuobinskoye oil and gas condensate field in Eastern Siberia [20].…”