- General information
Wellbore name
7120/1-1 R2
Type
EXPLORATION
Purpose
WILDCAT
Status
P&A
Factmaps in new window
Main area
BARENTS SEA
Well name
7120/1-1
Seismic location
TNGS 83 - 142 SP. 2891
Drilled in production licence
Drilling operator
A/S Norske Shell
Drill permit
480-L3
Drilling facility
Drilling days
126
Entered date
13.03.1986
Completed date
21.07.1986
Release date
21.07.1988
Publication date
11.04.2003
Purpose - planned
WILDCAT
Reentry
YES
Reentry activity
DRILLING/PLUGGING
Content
OIL/GAS SHOWS
Discovery wellbore
NO
Kelly bushing elevation [m]
25.0
Water depth [m]
342.0
Total depth (MD) [m RKB]
4003.0
Final vertical depth (TVD) [m RKB]
3978.0
Maximum inclination [°]
12.5
Bottom hole temperature [°C]
125
Oldest penetrated age
PRE-DEVONIAN
Oldest penetrated formation
BASEMENT
Geodetic datum
ED50
NS degrees
71° 55' 0.83'' N
EW degrees
20° 18' 7.13'' E
NS UTM [m]
7980020.26
EW UTM [m]
475816.85
UTM zone
34
NPDID wellbore
897
 
 
- Wellbore history
General
Well 7120/1-1 was drilled on the Alpha structure in the north of block 7120/1. The primary objective of the well was to test Palaeozoic carbonates and elastics in a partly fault-bounded/truncated dip closure on the western flank of the Loppa High. Potential Early Triassic sandstones in a low relief dip closure were a secondary objective.
Operations
Well 7120/1-1 was spudded on 16 August with the semi-submersible installation "Borgny Dolphin" and drilled to 2569 m where it was suspended on 15 November due to NPD drilling regulations during winter season. On 2 December permission was granted to continue operations and drilling continued to 2610 m. On 26 December the well was again suspended at the request of the Norwegian Petroleum Directorate because of safety considerations in adverse weather conditions. The well was re-entered on 13 March 1986 and drilled to a TD of 4003 m in basement rocks. The well was drilled with seawater and bentonite hi-vis pills down to 485 m. From there to TD gypsum/polymer mud was used with various "Lost Circulation Material" pills to cure mud losses.
The well encountered weak hydrocarbon shows from 800 m down to 2200 m  and oil shows in Late Permian carbonates (Tempelfjorden Group, Ørret Formation).  No intervals of significant reservoir potential were recognized from logs or described from cuttings in the Tertiary or Triassic sections. Below this sequence, three main Permian carbonate units were identified from logs and cuttings description. A porosity range of 5-10% for the limestone sequence between 2415 and 2461 m has been derived from log evaluation. In the basal part of this interval, a black shale was detected with a gas peak of 13% total gas. The lower limestone interval (2607-3277 m) contained weak fluorescence on cuttings from the top down to 2690 m.
No coring was attempted in the upper section of this unit due to severe mud losses to the formation. A core was recovered from the base of the interval where alternating limestone, clay stone, marl and shale were described with porosities in the order of 4%. In the lowermost interval (3310-3951 m), dolomite was described as the main lithology with porosities around 3%. No shows were registered. In general, the carbonates had low porosities, but two zones of higher porosity were detected from logs between 2810-2850 m and 2610-2660 m. Two production tests indicated that the limestone was permeable, but no pore fluids were produced.
Two cores were cut, one from 3186 m to 3194.5 m, a second from 4000 m – 4003 m in basement rocks. RFT fluid samples were taken at 2798 m ("Slight smell of hydrocarbons"), 3533 m, and 3714.5 m. Bottom hole temperatures from Wire line logging gave a maximum reading of 121 deg C at TD. True bottom hole temperature at TD is thus estimated to 125 °C. The well was plugged and abandoned as a dry hole with oil and gas shows on 21 July 1986.
Testing
Two production tests were carried out in the Upper Permian intervals 2810-2855 and 2607-2665 m. Neither interval flowed any pore fluids, not even after acid treatment. Upon nitrogen displacement treatment some fluids were produced, indicating that the formations in both intervals contained water with traces of natural gas, while the interval 2607-2665 m also produced some oil film. Attempts to analyse the oil failed due to the small amounts.
 
 
- Cores at the NPD
Core sample number
Core sample - top depth
Core sample - bottom depth
Core sample depth - uom
1
3185.8
3194.5
[m ]
2
4000.0
4002.3
[m ]
Total core sample length [m]
11.0
Cores available for sampling?
YES
 
 
- Core photos
Click to enlarge the pictureClick to enlarge the pictureClick to enlarge the pictureClick to enlarge the pictureClick to enlarge the picture
3186-3190m
3190-3195m
4000-4002m
  
     
 
 
- Lithostratigraphy
 
 
- Composite logs
Document name
Document format
Document size [KB]
pdf
0.74
 
 
- Geochemical information
Document name
Document format
Document size [KB]
pdf
0.72
pdf
1.57
 
 
- Documents - older NPD WDSS reports and other related documents
 
 
- Drill stem tests (DST)
Test number
From depth MD
[m]
To depth MD
[m]
Choke size
[mm]
1.0
2810
2855
25.4
2.0
2607
2665
6.4
Test number
Final shut-in pressure
[MPa]
Final flow pressure
[MPa]
Bottom hole pressure
[MPa]
Downhole temperature
[°C]
1.0
    
2.0
    
Test number
Oil
[Sm3/day]
Gas
[Sm3/day]
Oil density
[g/cm3]
Gas grav. rel.air
GOR
[m3/m3]
1.0
     
2.0
     
 
 
- Casing and leak-off tests
Casing type
Casing diam.
[inch]
Casing depth
[m]
Hole diam.
[inch]
Hole depth
[m]
LOT mud eqv.
[g/cm3]
Formation test type
CONDUCTOR
30
468.5
36
480.0
0.00
LOT
SURF.COND.
20
1101.0
26
1112.0
1.37
LOT
INTERM.
13 3/8
2093.0
17 1/2
2107.0
1.50
LOT
INTERM.
9 5/8
2414.0
12 1/4
2426.0
0.00
LOT
INTERM.
9 5/8
2414.0
12 1/4
2610.0
1.60
LOT
LINER
7
4003.0
8 1/2
4003.0
1.80
LOT
 
 
 
- Drilling mud
Depth MD [m]
Mud weight [g/cm3]
Visc. [mPa.s]
Yield point [Pa]
Mud type
Date measured
406
1.38
10.0
 
WATER BASED
 
567
1.39
10.0
 
WATER BASED
 
809
1.41
16.0
 
WATER BASED
 
2093
1.39
20.0
 
WATER BASED
 
2414
1.39
19.0
 
WATER BASED
 
2429
1.40
41.0
 
WATER BASED
 
2607
1.25
  
WATER BASED
 
2612
1.40
50.0
 
WATER BASED
 
2632
1.40
12.0
 
WATER BASED
 
2652
1.40
15.0
 
WATER BASED
 
2672
1.40
15.0
 
WATER BASED
 
2694
1.39
15.0
 
WATER BASED
 
2695
1.40
15.0
 
WATER BASED
 
2698
1.40
17.0
 
WATER BASED
 
2709
1.39
12.0
 
WATER BASED
 
2730
1.39
11.0
 
WATER BASED
 
2754
1.39
11.0
 
WATER BASED
 
2770
1.39
11.0
 
WATER BASED
 
2798
1.40
10.0
 
WATER BASED
 
2804
1.40
12.0
 
WATER BASED
 
2810
1.25
  
WATER BASED
 
2854
1.39
10.0
 
WATER BASED
 
2855
1.39
10.0
 
WATER BASED
 
2858
1.39
11.0
 
WATER BASED
 
2861
1.39
8.0
 
WATER BASED
 
2885
1.39
10.0
 
WATER BASED
 
2887
1.39
9.0
 
WATER BASED
 
2905
1.39
9.0
 
WATER BASED
 
2917
1.39
9.0
 
WATER BASED
 
2933
1.39
9.0
 
WATER BASED
 
2960
1.39
10.0
 
WATER BASED
 
2974
1.39
10.0
 
WATER BASED
 
3001
1.40
12.0
 
WATER BASED
 
3037
1.39
11.0
 
WATER BASED
 
3053
1.39
11.0
 
WATER BASED
 
3093
1.39
11.0
 
WATER BASED
 
3152
1.38
11.0
 
WATER BASED
 
3157
1.39
10.0
 
WATER BASED
 
3166
1.39
10.0
 
WATER BASED
 
3185
1.39
12.0
 
WATER BASED
 
3209
1.39
10.0
 
WATER BASED
 
3225
1.39
13.0
 
WATER BASED
 
3263
1.39
11.0
 
WATER BASED
 
3286
1.39
12.0
 
WATER BASED
 
3304
1.39
12.0
 
WATER BASED
 
3340
1.39
12.0
 
WATER BASED
 
3359
1.39
14.0
 
WATER BASED
 
3386
1.40
13.0
 
WATER BASED
 
3426
1.40
12.0
 
WATER BASED
 
3437
1.39
12.0
 
WATER BASED
 
3532
1.39
13.0
 
WATER BASED
 
3551
1.39
14.0
 
WATER BASED
 
3590
1.39
14.0
 
WATER BASED
 
3598
1.25
12.0
 
WATER BASED
 
3609
1.39
13.0
 
WATER BASED
 
3659
1.39
14.0
 
WATER BASED
 
3722
1.39
14.0
 
WATER BASED
 
3725
1.38
9.0
 
WATER BASED
 
3758
1.25
7.0
 
WATER BASED
 
3788
1.25
8.0
 
WATER BASED
 
3809
1.25
8.0
 
WATER BASED
 
3826
1.25
8.0
 
WATER BASED
 
3844
1.25
8.0
 
WATER BASED
 
3857
1.25
9.0
 
WATER BASED
 
3874
1.25
10.0
 
WATER BASED
 
3883
1.25
12.0
 
WATER BASED
 
3907
1.25
14.0
 
WATER BASED
 
3931
1.25
12.0
 
WATER BASED
 
3939
1.25
12.0
 
WATER BASED
 
3989
1.25
12.0
 
WATER BASED
 
4000
1.10
12.0
 
WATER BASED
 
4003
1.25
11.0
 
WATER BASED