Wellbore: 13.09.1991 - 2/7-26 S - Factpages - Norwegian Offshore Directorate

General information

General information
Attribute	Value
Wellbore name Official name of wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.	2/7-26 S
Type Wellbore type. Legal values: EXPLORATION, DEVELOPMENT, OTHER (see 'Purpose' for more information)	EXPLORATION
Purpose Final classification of the wellbore. Legal values for exploration wellbores: WILDCAT, APPRAISAL, WILDCAT-CCS, APPRAISAL-CCS. Legal values for development wellbores: OBSERVATION, PRODUCTION, INJECTION, INJECTION-CCS, OBSERVATION-CCS. Legal values for other wellbores: SOIL DRILLING (drilling in connection with track surveys and other subsurface surveys to investigate the soil conditions prior to placement of facilities), SHALLOW GAS (drilling to investigate shallow gas before the first 'real' drilling on the location), PILOT (drilling to investigate the geology and fluid connectors for location of the main wellbore), SCIENTIFIC (drilling according to Law of Scientific research and exploration), STRATIGRAPHIC (driling according to Law of Petroleum activities §2-1).	APPRAISAL
Status Status for the wellbore. Legal values are: BLOWOUT: A blowout has occurred in the well. CLOSED: A development wellbore that has been closed in a shorter or longer periode. Also applies to development wellbores where drilling is completed, but production/injection has not yet been reported. DRILLING: The well is in the drilling phase - can be active drilling, logging, testing or plugging, JUNKED: The drilling operation has been terminated due to technical problems. P&A: Exploration: The well is plugged and abandoned, and can not be reentered for further use. Development wells: The production/injection from/to the well is stopped and the well is plugged. The wellhead is removed or else made unavailable for further well operations. PLUGGED: The wellbore has been plugged, but the upper parts of the wellbore can be re-used. A sidetrack might be drilled at a later stage. PRODUCING: It was produced from the wellbore at the time of the operators last monthly report to the Norwegian Offshore Directorate. INJECTING: It was injected to the wellbore at the time of the operators last monthly report to the Norwegian Offshore Directorate. PREDRILLED: The upper part of the well has been drilled, usually as part of a batch-drilling campaign covering several wellbores. RE-CLASS TO DEV: Exploration wellbore that is reclassified to a development wellbore. RE-CLASS TO TEST: Exploration wellbore that is reclassified to test production. SUSPENDED: The drilling operation in the wellbore has been temporarily stopped. The current plan is to continue drilling later on.	RE-CLASS TO DEV
Factmaps in new window	link to map
Main area Name of the area on the Norwegian Continental Shelf where the wellbore is located. Legal values: BARENTS SEA, NORWEGIAN SEA, NORTH SEA.	NORTH SEA
Field Name of the field the wellbore is related to.	EMBLA
Discovery Name of the discovery the wellbore is related to.	2/7-20 Embla
Well name Official name of the parent well for the wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.	2/7-26
Seismic location Position of spud location on seismic survey lines. SP: shotpoint.	PC-88 LINE 369 & COLUMN 1061
Production licence Official designation of the production licence the wellbore was drilled or planned to be drilled from ( well head posistion).	018
Drilling operator Name of the licensee starting the drilling operation on behalf of the active production license (well head position). This will usually equal the operator of the production license.	Phillips Petroleum Company Norway
Drill permit The drilling permit number together with the version of the drilling permit as stated in the drilling permit granted by the Norwegian Offshore Directorate.	674-L
Drilling facility Norwegian Offshore Directorate's name of the facility which the wellbore was drilled from.	WEST DELTA
Drilling days Number of days from wellbore entry to wellbore completion.	178
Entered date The date when he wellbore was spudded. For sidetracks: The date when new formation was drilled by kicking off from the mother-wellbore,	20.03.1991
Completed date Exploration wellbores from moveable facilities: For floating facilities - date when anchor handling is started. For jackups - date the jacking-down started. Exploration wellbores from fixed facilities and all development wellbores: Date when the wellbore is at total depth, and last casing, liner or screen is set. In case of immediate plugging of the wellbore, completed date equals the date the last plug i set in the wellbore. Date when the wellbore is at total depth, and last casing, liner or screen is set. In case of immediate plugging of the wellbore, completed date equals the date the last plug i set in the wellbore.	13.09.1991
Release date Date when raw data which has been reported to the authorities from the wellbore is not confidential any longer. Normally 2 years after finishing the drilling. May be earlier if the area of the production license is relinquished.	13.09.1993
Publication date Date quality control of the wellbore information was completed, so it can be published on the internet as a 'Well Data Summary Sheet' wellbore with more information available than other wellbores.	26.05.2009
Purpose - planned Pre-drill purpose of the wellbore. Legal values for exploration wellbores: WILDCAT, APPRAISAL, WILDCAT-CCS, APPRAISAL-CCS. Example of legal values for development wellbores: OBSERVATION, PRODUCTION, INJECTION.	APPRAISAL
Reclassified to wellbore	2/7-D-26
Reentry Status whether the wellbore has been re-entered (YES) or not (NO). Re-entered wellbores are not included in the count when wellbores are presented in statistical overviews.	NO
Content For exploration wellbores, status of discovery. Legal values: DRY, SHOWS (trace amounts of hydrocarbons), GAS, GAS/CONDENSATE, OIL or OIL/GAS. SHOWS (GAS SHOWS, OIL SHOWS or OIL/GAS SHOWS) are detected as fluorescent cut (organic extract), petroleum odour, or visual stain on cuttings or cores, or as increased gas reading on the mud-loggers gas detection equipment. Legal values for WILDCAT-CCS and APPRAISAL-CCS: WATER For development wellbores, type of produced/injected fluid. Legal values: WATER, CUTTINGS, NOT AVAILABLE, OIL, GAS/CONDENSATE, OIL/GAS, CO2, GAS, WATER/GAS, NOT APPLICABLE.	OIL
Discovery wellbore Indicator which tells if the wellbore made a new discovery. Legal values: YES, NO. Prior to press-release or other information regarding drilling results, the indicator will be “NO” as a default.	NO
1st level with HC, age Age of lithostratigraphic unit, 1st level, where hydrocarbons were encountered. Examples of legal values: CRETACEOUS, EARLY CRETACEOUS, LATE JURASSIC, EOCENE. See also Norwegian Offshore Directorate bulletins.	DEVONIAN
1st level with HC, formation Name of lithostartigraphic unit, 1st level, where hydrocarbons were encountered. Shown only for released wells. Examples of legal values: BASEMENT, COOK FM, EKOFISK FM, HEIMDAL FM, SANDNES FM, SOGNEFJORD FM, TARBERT FM, BRENT GP. See also Norwegian Offshore Directorate bulletins.	NO GROUP DEFINED
Kelly bushing elevation [m] Elevation of the rotary kelly bushing (RKB) above mean sea level.	29.0
Water depth [m] Depth in metres betweem mean sea level and sea floor.	70.8
Total depth (MD) [m RKB] Total measured length of wellbore from kelly bushing to total depth (driller's depth).	4848.0
Final vertical depth (TVD) [m RKB] Vertical elevation from total depth to kelly bushing. Shown only for released wells. Referred to as true vertical depth (TVD).	4697.0
Maximum inclination [°] Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.	24
Bottom hole temperature [°C] Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.	167
Oldest penetrated age Age (according to Geologic Time Scale 2004 by F. M. Gradstein, et al. (2004)) of the oldest penetrated formation. May differ from age at TD for example in deviated wellbores. Examples of legal values: CRETACEOUS, EARLY CRETACEOUS, LATE JURASSIC, EARLY PERMIAN, EARLY TRIASSIC, EOCENE.	DEVONIAN
Oldest penetrated formation Name of the oldest lithostratigraphic unit penetrated by the wellbore. Shown only for released wells. In most wellbores this is formation or group at total depth. May differ from formation or group at TD for example in wellbores drilled with high deviation or through faults. Examples of legal values: AMUNDSEN FM, BALDER FM, BASEMENT, BLODØKS FM, BRYNE FM, BURTON FM, COOK FM, DRAKE FM, DRAUPNE FM, EKOFISK FM, DUNLIN GP.	NO GROUP DEFINED
Geodetic datum Reference system for coordinates. Example of legal values: ED50.	ED50
NS degrees Geographic coordinate of the wellhead, north-south degrees.	56° 19' 59.59'' N
EW degrees Geographic coordinate of the wellhead, east-west degrees.	3° 14' 53.55'' E
NS UTM [m] Universal Transverse Mercator coordinate of the wellhead, north-south.	6243333.20
EW UTM [m] Universal Transverse Mercator coordinate of the wellhead, east-west.	515347.49
UTM zone Universal Transverse Mercator zone. Examples of legal values: 31, 32, 33, 34.	31
NPDID wellbore Norwegian Offshore Directorate's unique id for the wellbore.	1756

Well 2/7 26 S is located on the Embla Field in the Central Graben of the North Sea. It was designed to test the pre-Jurassic sandstones, which had shown commercial quantities of hydrocarbons in the 2/7-20, 2/7-21 S, and 2/7-23 S wells. The objective of the well was to confirm the presence of hydrocarbon bearing sandstones in the western fault block of the structure and to establish the productivity of this reservoir section through a program of well testing and coring. Well location and TD was chosen so that both the upper and lower sandstone members of the pre-Jurassic sequence would be penetrated. The target location was 300 m to the south of the 2/7-9 well at Base Cretaceous level. The reservoir section was expected to be highly fractured and over-pressured. Shallow gas was expected since gas had been encountered in all wells drilled from the template location over the 2/7-20 well.

Operations and results

Appraisal well 2/7 26 S was spudded with the semi-submersible installation West Delta on 20 March 1991 and drilled to TD at 4848 in Devonian rocks. The well was drilled deviated from a template located over the 2/7-20 well to penetrate the target reservoir section in the western fault block of the Embla structure. Minor shallow gas was detected in sandy zones with an increase in background gas from 4 to 64 units. Apart from some failures when logging and some stuck pipe experiences, drilling proceeded without significant problems. The well was drilled with seawater and hi-vis sweeps down to 575 m, with KCl/PAC mud from 575 m to 4125.5 m, and with Enviromul oil based mud from 4125.5 m to TD.

The 9 5/8" casing was set in claystones of the Lower Cretaceous, Rødby Formation. The remaining Lower Cretaceous section including Sola, Tuxen and Åsgård Formations was penetrated, followed by a Late Jurassic sequence consisting of 3 m Mandal Formation and 82 m Farsund Formation. The top of the reservoir sands were encountered at 4386 m (4226 m TVD), 58 m higher than prognosed. As in the other Embla wells the reservoir was undefined, Pre-Jurassic stratigraphy. Both the upper and the lower sandstone units were present in the well as predicted. The reservoir was oil bearing. No definite OWC was defined, however RFT pressure data, logs and DST results indicated oil-filled porous sandstones from top reservoir and down to at least 4606 m (4465 m TVD).

The cuttings in the intervals between 1520 - 1680 m and 1730 - 1830 m (Base Nordland Group / upper Hordaland Group) showed 30-100% pale to bright yellow fluorescence accompanied by oil in the mud. The cut was blooming to streaming yellow, and the odour was good to strong. Good to excellent oil shows were seen in the interval 3111.4 m to 3973 m with 35% fluorescence in marls/limestones from 3111.4 m and rapidly increasing to 70% by 3018.1 m. Shows up to 80%, with bright yellow fluorescence and yellow fast streaming cut, were seen from 3124.2 to 3230.9 m. Shows were also seen at 3550.9 m, 5% -10% with dull yellow fluorescence and hazy crushed cut. From 3627.1 to 3834.4 m shows of 20% to 80% with a dull fluorescence were seen. The cut was pale blue yellow and slightly streaming. Shows further down in the well, including the pre-Jurassic reservoir section were weak and most likely caused by the oil-based mud.

A total of 18 cores were cut in the well. The first was cut at 3200.4 - 3214.3 m in the Tor Formation. The second core was cut through the Mandal Formation and into the upper part of the Farsund Formation. A total of 16 cores were cut in the reservoir interval including a core in the rhyolittic rocks at TD. A total of 90 sidewall cores were attempted and 28 sidewall cores were recovered. No wire line fluid samples were taken.

The well was suspended on 13 September 1991 as an oil appraisal well and reclassified to development well 2/7-D-26

Testing

Two DST tests were performed in this well.

DST 1 was conducted over the interval 4605.5 - 4696.9 m (4465.0 - 4552.2 m TVD). It flowed in the range of 48 Sm3 (300 STB) /day, with signs of unstable flow, at pressures less than 1000 psi.

DST 2 was conducted over a gross interval from 4309.8 - 4538.4 (4184 - 4401 m TVD).The well was tested on a 16/64" choke with flowing rates of 223 Sm3 oil and 61447 Sm3 gas/day. The GOR was 275 Sm3/Sm3, the oil density was 0.81 g/cm3 (43 deg API), and the gas gravity (air = 1) was 0.81 with 6% CO2 and 20 ppm H2S. A stable down-hole temperature of 160 deg C was measured in the test.

Cuttings at the Norwegian Offshore Directorate

Cuttings at the Norwegian Offshore Directorate
Cuttings available for sampling?	YES

Cuttings at the Norwegian Offshore Directorate
Cutting sample, top depth [m]	Cutting samples, bottom depth [m]
579.00	4547.60

Cores at the Norwegian Offshore Directorate

Cores at the Norwegian Offshore Directorate
Core sample number	Core sample - top depth	Core sample - bottom depth	Core sample depth - uom
1	10500.0	10545.5	[ft ]
2	14103.0	14153.9	[ft ]
3	14417.0	14453.1	[ft ]
4	14457.0	14480.8	[ft ]
5	14481.0	14545.8	[ft ]
6	14558.0	14581.6	[ft ]
7	14586.0	14592.1	[ft ]
8	14598.0	14635.6	[ft ]
9	14636.0	14658.0	[ft ]
10	14660.0	14693.6	[ft ]
11	14696.0	14743.8	[ft ]
12	14746.0	14807.2	[ft ]
13	14807.0	14848.0	[ft ]
14	14854.0	14903.6	[ft ]
15	14903.0	14935.6	[ft ]
16	15312.0	15403.6	[ft ]
17	15404.0	15495.1	[ft ]
18	15844.0	15907.7	[ft ]

Cores at the Norwegian Offshore Directorate
Total core sample length [m]	250.7

Cores at the Norwegian Offshore Directorate
Cores available for sampling?	YES

Core photos

Core photos

5480-5487ft	10500-10510ft	10510-10522ft	10522-10534ft	10534-10545ft

14103-14118ft	14118-14133ft	14133-14148ft	14148-14153ft	14417-14432ft

14432-14447ft	14447-14453ft	14457-14472ft	14472-14480ft	14481-14496ft

14496-14511ft	14511-14526ft	14526-14541ft	14541-14545ft	14558-14573ft

14573-14581ft	14586-14592ft	14598-14613ft	14613-14628ft	14628-14635ft

14636-14651ft	14651-14658ft	14660-14675ft	14675-14690ft	14790-14693ft

14696-14711ft	14711-14726ft	14726-14741ft	14741-14743ft	14746-14761ft

14761-14776ft	14776-14791ft	14791-14806ft	14806-14807ft	14807-14822ft

14822-14837ft	14854-14869ft	14869-14884ft	14884-14899ft	14899-14903ft

14903-14918ft	14918-14933ft	14933-14935ft	15312-15327ft	15327-15342ft

15342-15357ft	15357-15372ft	15372-15387ft	15387-15402ft	15402-15403ft

15404-15419ft	15419-15434ft	15434-15449ft	15449-15464ft	15464-15479ft

15479-15494ft	15494-15495ft	15844-15859ft	15859-15874ft	15874-15889ft

15889-15904ft	15904-15907ft

Oil samples at the Norwegian Offshore Directorate

Oil samples at the Norwegian Offshore Directorate
Test type	Bottle number	Top depth MD [m]	Bottom depth MD [m]	Fluid type	Test time	Samples available
DST	DST 1	4605.50	4696.90		24.08.1991 - 00:00	YES
DST	DST 2	4309.80	4538.40		03.09.1991 - 00:00	YES

Lithostratigraphy

Lithostratigraphy
Top depth [mMD RKB]	Lithostrat. unit
100	NORDLAND GP
1606	HORDALAND GP
2966	ROGALAND GP
2966	BALDER FM
2983	SELE FM
3038	LISTA FM
3091	VÅLE FM
3118	SHETLAND GP
3118	EKOFISK FM
3200	TOR FM
3321	HOD FM
3981	BLODØKS FM
3989	HIDRA FM
4057	CROMER KNOLL GP
4057	RØDBY FM
4163	TUXEN FM
4182	ÅSGARD FM
4299	TYNE GP
4299	MANDAL FM
4302	FARSUND FM
4386	NO GROUP DEFINED

Documents – older Norwegian Offshore Directorate WDSS reports and other related documents

Documents – older Norwegian Offshore Directorate WDSS reports and other related documents
Document name	Document format	Document size [MB]
1756_01_WDSS_General_Information	pdf	0.58
1756_02_WDSS_completion_log	pdf	0.25

Documents – reported by the production licence (period for duty of secrecy expired)

Documents – reported by the production licence (period for duty of secrecy expired)
Document name	Document format	Document size [MB]
1756_2_7_26_S_COMPLETION_LOG	pdf	2.75
1756_2_7_26_S_COMPLETION_REPORT_2	pdf	38.80

Drill stem tests (DST)

Drill stem tests (DST)
Test number	From depth MD [m]	To depth MD [m]	Choke size [mm]
1.0	4606	4697	6.3
2.0	4310	4538	6.3

Drill stem tests (DST)
Test number	Final shut-in pressure [MPa]	Final flow pressure [MPa]	Bottom hole pressure [MPa]	Downhole temperature [°C]
1.0				133
2.0

Drill stem tests (DST)
Test number	Oil [Sm3/day]	Gas [Sm3/day]	Oil density [g/cm3]	Gas grav. rel.air	GOR [m3/m3]
1.0	53	10123	0.819		191
2.0	223	61447	0.819	0.810	279

Logs

Logs
Log type	Log top depth [m]	Log bottom depth [m]
CST GR	4145	4829
CST GR	4147	4777
DLL MSFL BHC GR AMS	2133	4104
FMS GR	3112	4083
LDL CNL GR AMS	3088	4070
LDL CNL NGL AMS	4256	4859
MWD - GR RES DIR	274	4394
OBDT GR	4120	4857
PIL ASL GR AMS	3977	4856
RFT GR	3134	3530
RFT GR	4174	4715
VELOCITY	2255	4800

Casing and leak–off tests

Casing and leak–off tests
Casing type	Casing diam. [inch]	Casing depth [m]	Hole diam. [inch]	Hole depth [m]	LOT/FIT mud eqv. [g/cm3]	Formation test type
CONDUCTOR	30	158.0	36	160.0	0.00	LOT
INTERM.	20	571.0	26	573.0	0.00	LOT
INTERM.	13 3/8	2130.0	17 1/2	2133.0	1.91	LOT
INTERM.	9 5/8	4117.0	12 1/4	4120.0	2.16	LOT
INTERM.	6 5/8	4847.0	8 1/8	4848.0	0.00	LOT

Drilling mud

Drilling mud
Depth MD [m]	Mud weight [g/cm3]	Visc. [mPa.s]	Mud type
118	1.05		WATER BASED
160	1.05		WATER BASED
180	1.05		WATER BASED
294	1.05		WATER BASED
576	1.20		WATER BASED
694	1.32	35.0	OIL BASED
1178	1.32	38.0	OIL BASED
1628	1.56	42.0	OIL BASED
1991	1.70	32.0	OIL BASED
2143	1.70	26.0	OIL BASED
2146	1.70	38.0	OIL BASED
2288	1.70	18.0	OIL BASED
2473	1.70	18.0	OIL BASED
2630	1.70	20.0	OIL BASED
2724	1.70	19.0	OIL BASED
2874	1.73	21.0	OIL BASED
2983	1.73	22.0	OIL BASED
2987	1.73	22.0	OIL BASED
2998	1.73	23.0	OIL BASED
3047	1.73	21.0	OIL BASED
3125	1.73	22.0	OIL BASED
3138	1.73	22.0	OIL BASED
3200	1.73	21.0	OIL BASED
3219	1.73	26.0	OIL BASED
3341	1.73	21.0	OIL BASED
3385	1.73	20.0	OIL BASED
3487	1.73	24.0	OIL BASED
3498	1.73	24.0	OIL BASED
3532	1.73	22.0	OIL BASED
3625	1.73	26.0	OIL BASED
3678	1.73	26.0	OIL BASED
3749	1.73	27.0	OIL BASED
3772	1.73	26.0	OIL BASED
3778	1.73	26.0	OIL BASED
3783	1.75	26.0	OIL BASED
3987	1.75	24.0	OIL BASED
3999	1.75	24.0	OIL BASED
4062	1.75	26.0	OIL BASED
4073	1.75	23.0	OIL BASED
4113	1.93	35.0	WATER BASED
4116	1.75	22.0	OIL BASED
4126	1.76	26.0	OIL BASED
4146	2.00	52.0	WATER BASED
4208	2.02	53.0	WATER BASED
4256	2.02	49.0	WATER BASED
4279	2.04	46.0	OIL BASED
4299	2.02	44.0	WATER BASED
4314	2.02	44.0	WATER BASED
4315	2.04	45.0	WATER BASED
4331	2.04	45.0	WATER BASED
4362	2.06	49.0	WATER BASED
4394	2.06	50.0	WATER BASED
4394	2.06	49.0	WATER BASED
4407	2.04	55.0	WATER BASED
4414	2.06	49.0	WATER BASED
4436	2.06	50.0	WATER BASED
4450	2.06	50.0	WATER BASED
4468	2.06	49.0	WATER BASED
4479	2.06	49.0	WATER BASED
4523	2.06	54.0	WATER BASED
4542	2.04	48.0	WATER BASED
4553	2.04	53.0	WATER BASED
4554	2.04	52.0	WATER BASED
4602	2.04	46.0	WATER BASED
4657	2.04	43.0	OIL BASED
4723	2.04	46.0	WATER BASED
4849	2.04	42.0	WATER BASED
4849	2.04	42.0	OIL BASED

Pressure plots

Pressure plots
The pore pressure data is sourced from well logs if no other source is specified. In some wells where pore pressure logs do not exist, information from Drill stem tests and kicks have been used. The data has been reported to the NPD, and further processed and quality controlled by IHS Markit.

Pressure plots
Document name	Document format	Document size [MB]
1756_Formation_pressure_(Formasjonstrykk)	pdf	0.22

2/7-26 S