31 Jul 2013 07:00
JKX OIL & GAS plc ("JKX")
Progress Report on R-103 Frac in Ukraine
JKX Oil & Gas plc ("JKX") is pleased to provide details of the first three out of nine stages of the well R-103 frac which were completed successfully. An interim flow back has been performed for preliminary clean-up of the formation, and work has now started on stages four to six of the programme. Each stage covers approximately 100m of the sub-horizontal 1,000m reservoir section.
Stage 1, at the toe of the well, represented the deepest and poorest lithology section. All phases went smoothly: the abrasive jetting, which cut five sets of four holes perpendicular to each other over a one metre interval, was effective, and was followed by the first mini-frac. This established the frac pressure and the expected frac dimensions. The contractor was successful in pumping away around 50 tons of proppant carried by just over 400 cubic metres of frac fluid and gel.
The pressure during pumping reached 620 bar (8,992 psi) and the maximum pump rate achieved was 3.9 cubic metres per minute, or 34,000 barrels per day. The propped frac length was calculated at 131m with an average propped width of 3.6mm. After a short clean-out of any leftover proppant and fluid, the contractor set and tested the next bridge plug to isolate Stage 1 from Stage 2.
Stage 2 was a more difficult operation when, after some delays due to technical problems, the mini-frac demonstrated that the pressure required to frac this particular interval of rock exceeded our equipment safe limit of 690 bar (10,000 psi). A second interval was selected some 20 metres further along the well and, after an extended period of pumping, the formation broke down at an acceptable pressure.
Thereafter, the operation went more smoothly. The main frac took over 100 tons of proppant and 624 cubic metres of fluid and gel (3,925 barrels) at a maximum rate of 5.14 cubic metres per minute (47,000 barrels per day) with a pump pressure of 580 bar (8,400psi). Estimated propped frac length was 138m with an average propped width of 6.2mm.
Stage 3 was executed to plan. Total volume of proppant was 118 tons, total volume of fluid and gel was 120 tons, total volume of gel and fluid was 644 cubic metres and the pump rate was 3.91 cubic metres per minute (35,000 barrels per day) with a pump pressure of 655 bar (9,500psi). The propped frac length worked out at 204m with an average width of 4.9mm.
The plugs separating the first three stages were then drilled out and nitrogen lift was applied to help start the fluid recovery. With over 2,000 cubic metres (12,500 barrels) of liquid injected, this was a slow process, but the pressure in the reservoir was sufficient to flow back the liquid and, after around 24 hours, the well was flowing without nitrogen lift.
The next three stages have now been commenced and it is planned to repeat the clean-out procedure after Stage 6, with full clean-out and testing after the completion of the final Stage 9 frac. Based on progress to date, this should be by the end of August. Initial results are expected at the end of Q3.
It has been noted that the pressures required for a successful frac are close to the safe working limit of the equipment. Additional equipment has been mobilised to permit higher surface pressures if required.
JKX's Chief Executive Dr Paul Davies, commented: "Operationally this complex programme has made very good progress and we now have three fracs completed successfully. We are seeing variability in the rock properties as we progress along the well bore, and we may encounter sections where the pump pressure to frac the rock exceeds the safe working limit of the equipment. We have, therefore mobilised additional equipment which should help us partially overcome the high break-down pressures encountered. I look forward to reporting progress with the next three stages of the programme."
JKX Oil & Gas plc is an exploration and production company listed on the London Stock Exchange. The Company has licence interests in Ukraine, Russia, Hungary and Slovakia.
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For further information please contact:
Nadja Vetter / Lauren Foster, Cardew Group T: 020 7930 0777