Fishbone Stimulation a Game Changer for Tight Carbonate Productivity Enhancement, Case Study of First Successful Implementation at Adnoc Onshore Fields

Abstract

Productivity enhancement of tight carbonate reservoirs (permeability 1-3 md) is critical to deliver the mandated production and to achieve the overall recovery. However, productivity improvement with conventional acid stimulation is very limited and short-lived. Tight reservoirs development with down spacing and higher number of infill wells can increase the oil recovery. Nevertheless, poor vertical communication (Kv/Kh < 0.5) within the layered reservoir is still a challenge for productivity enhancement and needs to be improved. First time successful installation of fishbone stimulation technology at ADNOC Onshore targeted establishing vertical communication between layers, in addition to maximizing the reservoir contact. Furthermore this advanced stimulation technology connects the natural fractures within the reservoir, bypasses near well bore damage and allows the thin sub layers to produce. This technology requires running standard lower completion tubing with Fishbone subs preloaded with 40ft needles, and stimulation with rig on site. This paper presents the case study of the fishbone stimulation technology implemented at one of the tight-layered carbonate reservoir. A new development well from ADNOC Onshore South East field was selected for implementation of this technology. The well completion consisting of 4 ½ liner with 40 fishbone subs was installed, each sub containing four needles at 90 degrees phasing capable of penetrating the reservoir up to 40 ft. While rig on site, acid job was conducted for creating jetting effect to penetrate the needles into the formation. Upon completion of jetting operation, fishbone basket run cleaned the unpenetrated needles present in the liner to establish the accessibility up to the total depth. Overall, application of this technology improved the well production rate to 1600 BOPD compared to 400 BOPD of production from nearby wells in the same PAD and reservoir. In addition the productivity of the candidate well improved by 2.5 times with respect to near-by wells in the same PAD. Currently, long-term sustainability testing preparation is in progress. This paper provides the details of candidate selection, completion design, technology limitations, operational challenges, post job testing and lessons learned during pilot implementation. In summary, successful application of this technology is a game changer for tight carbonate productivity enhancement that improves the overall recovery along with optimizing the drilling requirements. Currently, preparation for implementation of 10 pilots in one of the asset at ADNOC Onshore fields is in progress.

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].…”

A Novel Approach by Needles in the Payzone of Heterogeneous Tight Carbonate: A Case Study for Offshore Marginal Field

“…One is that severe losses happened based on FCS experience in the field [15][16][17][18][19][20]. Another is a significant risk for fishing basket needle recovery as it is failed case [21].…”

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

“…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]. In the UAE, successful FbD case studies have been reported in naturally fractured reservoirs [21,22], and an innovative Fishbone infill well was applied in the Canadian oil sands play [23]. Research into applications of Fishbone well configurations in areas such as geothermal drilling, enhanced oil recovery, steam-assisted gravity drainage, and underground saltwater disposal are ongoing [24,25].…”