Arbuzovskoye Oil Field
The Arbuzovskoye field (formerly Varyakhskaya prospect) is located in the north central part of License 61 about 10 km east of the Lineynoye oil field. This structure was delineated and prepared for drilling by seismic data in 1990-91. Additional seismic data was obtained by PetroNeft in 2005/2006. The Arbuzovskoye No. 1 discovery well was drilled in 2010. The well tested open hole with an inflow of 289 bopd from Upper Jurassic J1 sandstones (2,557.3 to 2,586.0 m MD). A step rate DST was performed and stabilised flow on an 8 mm choke was 176 bopd (2,564.9 to 2,570.9 m MD). The oil is high quality with a density of 0.79 g/cm3 (47 degree API gravity).
According to the log interpretation the Upper Jurassic J1-1 sandstone was penetrated from 2,565.8 to 2,573.2 m tvdss (true vertical depth subsea). The reservoir is completely saturated with oil throughout and the effective net oil pay is 5.1 metres.
The RF State Reserves Committee (RKZ) approved C1+C2 reserves for the field at 10 million barrels and the Pilot Production Project for field development was approved by the RF Central Development Commission in November 2011.
A 10 km pipeline and utility line were constructed from the Lineynoye central processing facility to the Arbuzovskoye field in Q1 2012. Production through the pipeline commenced in May 2012 from the Arbuzovskoye No. 1 discovery well. Drilling of additional development wells commenced in August 2012 and good results were achieved particularly from the A-101 and A-102 wells which achieved initial rates of 310 and 540 bopd respectively. The initial development drilling programme consisting of 6 wells drilled from Pad 1 was completed in March 2013.
Ryder Scott estimated the proved and probable reserves for the field at 6.54 million bbls at 1 April 2013. The 3P reserves for the field were estimated at 8.23 million bbls.
Following the farmout of 50% of Licence 61 to Oil India in July 2014 the drilling was recommenced at Arbuzovskoye Pad 1. In the period from September 2014 to March 2015, four additional production wells and one water injection well were drilled. This was a successful drilling programme which confirmed the oil water contact for the field at -2.479 m tvdss which is consistent the structural spill point at -2,480 m tvdss based on the seismic interpretation.
The A-103 well which was 15 m high to prognosis at the top of the reservoir confirmed oil in the southern lobe of the Arbuzovskoye structure. This result makes the southern lobe of the field both higher and broader than previously interpreted. Additional seismic data acquired over the field in 2015 also confirmed this result.
Development of the southern portion of the Arbuzovskoye was carried out in 2016. The development consisted of 2 horizontal wells and two vertical wells. Additional infrastructure included a 4.2 km pipeline and utility line to tie back to Arbuzovskoye Pad 1 and the standard Pad "Kit" (transformer station, ESP control module, test separator, quarters building, etc.).
The initial vertical control well (A-213) contained oil in both the J1-1 and J1-2 reservoir intervals. The J1-2 interval was perforated initially and produced at a stabilized rate of about 150 bopd. This was the first J1-2 production at the Arbuzovskoye oil field. The J1-1 interval was added later and the combined intervals initially produced at a rate over 400 bopd. The A-214 and A-215 horizontal wells were then drilled. These wells were about 1,000 m in length and contained 931 m and 809 m of net pay respectively. Initial flow rates were about 900 bopd and 650 bopd respectively. It should be noted that the first horizontal well at Arbuzovskoye (A-214) with an initial flow rate of about 900 bopd is the best flow rate thus far in the licence area. Based on the good results of the initial 3 wells, an additional well (A-216) was added to the programme. The well contained about 11.4 m of net pay in the J1-1 and J1-2 intervals. Initial production was about 175 bopd, but the water cut in the well quickly increased due to coning of water from below the oil water contact in the J1-2 interval. Work over options to reduce the water flow in the well are under review.
