Wellbore: 27.02.1980 - 31/2-2 - 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.	31/2-2
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.	SUSPENDED
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.	TROLL
Discovery Name of the discovery the wellbore is related to.	31/2-1 (Troll Vest)
Well name Official name of the parent well for the wellbore based on Norwegian Offshore Directorate guidelines for designation of wells and wellbores.	31/2-2
Seismic location Position of spud location on seismic survey lines. SP: shotpoint.	79416 SP.200
Production licence Official designation of the production licence the wellbore was drilled or planned to be drilled from ( well head posistion).	054
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.	A/S Norske Shell
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.	241-L
Drilling facility Norwegian Offshore Directorate's name of the facility which the wellbore was drilled from.	WEST VENTURE OLD
Drilling days Number of days from wellbore entry to wellbore completion.	57
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,	27.02.1980
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.	23.04.1980
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.	23.04.1982
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.	23.05.2006
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.	WILDCAT
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/GAS
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.	LATE JURASSIC
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.	SOGNEFJORD FM
Kelly bushing elevation [m] Elevation of the rotary kelly bushing (RKB) above mean sea level.	32.0
Water depth [m] Depth in metres betweem mean sea level and sea floor.	323.0
Total depth (MD) [m RKB] Total measured length of wellbore from kelly bushing to total depth (driller's depth).	1857.0
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).	1857.0
Maximum inclination [°] Maximum deviation, in degrees, from a vertical well path.Shown only for released wells.	1.25
Bottom hole temperature [°C] Estimated temperature at final total depth of the wellbore. Shown only for released wells. See discription.	43
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.	MIDDLE JURASSIC
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.	KROSSFJORD FM
Geodetic datum Reference system for coordinates. Example of legal values: ED50.	ED50
NS degrees Geographic coordinate of the wellhead, north-south degrees.	60° 46' 47.8'' N
EW degrees Geographic coordinate of the wellhead, east-west degrees.	3° 37' 23.5'' E
NS UTM [m] Universal Transverse Mercator coordinate of the wellhead, north-south.	6738597.32
EW UTM [m] Universal Transverse Mercator coordinate of the wellhead, east-west.	533940.27
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.	227

Well 31/2-2 was drilled some 4 km east of the discovery well 31/2-1 on seismic line 79-416 at SP 200. The concession requirement for the wells were complete penetration of the prospective Jurassic sequence and terminate in Triassic or older. The particular objectives of well 31/2-2 were: to evaluate lateral variation of reservoir parameters eastwards on the flank of the structure: to test the zone of oil shows seen in 31/2-1 in better reservoir conditions, to test the gas accumulation in a down-dip location: to evaluate the nature of the seismic flatspot, and to provide geological calibration of seismic reflectors above the reservoir for improved regional evaluation.

Operations and results

Well was spudded with the semi-submersible installation West Venture on 27 February 1980 and drilled to TD at 1857 m in the Middle Jurassic Krossfjord Formation. The 36" hole was drilled without incident to 433 m using seawater with viscous pills spotted on connections. From 422 m to 433 m hard drilling was experienced. This was interpreted as a boulder bed similar to that found at a comparable depth in the previous 31/2-1 well. Problems were encountered with the stability of the temporary guide base, and the well had to be abandoned. The rig was moved NE 25 m and re-spudded on 29 February. The well was drilled with seawater and hi-vis pills down to 800 m, and with gypsum/lignosulphonate mud from 800 m to TD.

Top reservoir (Sognefjord Formation) came in at 1544 m and was gas bearing down to a gas/oil contact at 1579 m, and oil-bearing from 1579 m down to an oil/water contact at 1591 m. Both contacts were clearly defined on logs, the gas/oil contact was confirmed by RFT pressure gradients, and moveable oil was confirmed by RFT sampling at 1587.5 m and 1590 m. Gas samples were obtained from 1548 m and 1571 m. Weak oil shows began at 1561 m in the gas zone, strong shows with stained and bleeding cores and a paraffinic smell were observed in the oil zone. Oil shows ceased at 1602 m.

Coring started at 1515 m in the Draupne Formation and terminated below the oil-water contact. A 120 m interval was cored with 94.2 m of core in 13 cores recovered at surface.

After coring and logging of the Late Jurassic sandstones the well was suspended at the 9 5/8 casing shoe and the rig towed to Bergen for inspection and repairs on 22 April 1980.

Testing

No drill stem test was performed

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]
490.00	2600.00

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	1515.0	1521.1	[m ]
2	1525.0	1527.0	[m ]
3	1535.0	1547.6	[m ]
4	1553.0	1560.0	[m ]
5	1560.0	1569.0	[m ]
6	1569.0	1578.0	[m ]
7	1578.0	1581.0	[m ]
8	1585.0	1598.0	[m ]
9	1598.0	1603.6	[m ]
10	1604.0	1606.4	[m ]
11	1608.0	1617.0	[m ]
12	1617.0	1626.0	[m ]
13	1626.0	1632.5	[m ]

Cores at the Norwegian Offshore Directorate
Total core sample length [m]	94.2

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

Core photos

Core photos

1515-1517m	1517-1520m	1520-1521m	1525-1527m	1535-1537m

1537-1540m	1540-1543m	1543-1545m	1545-1547m	1555-1558m

1558-1560m	1560-1562m	1562-1565m	1565-1568m	1568-1569m

1569-1571m	1574-1577m	1578-1580m	1585-1587m	1587-1590m

1590-1593m	1593-1595m	1595-1598m	1598-1600m	1600-1603m

1603-1604m	1604-1606m	1608-1610m	1610-1611m	1616-1617m

1617-1618m	1619-1621m	1622-1623m	1624-1626m	1626-1628m

1628-1631m	1631-1632m

Palynological slides at the Norwegian Offshore Directorate

Palynological slides at the Norwegian Offshore Directorate
Sample depth	Depth unit	Sample type	Laboratory
870.0	[m]	DC	GEOCH
900.0	[m]	DC	GEOCH
930.0	[m]	DC	GEOCH
960.0	[m]	DC	GEOCH
990.0	[m]	DC	GEOCH
1167.0	[m]	DC	GEOCH
1203.0	[m]	DC	GEOCH
1233.0	[m]	DC	GEOCH
1263.0	[m]	DC	GEOCH
1287.0	[m]	DC	GEOCH
1317.0	[m]	DC	GEOCH
1347.0	[m]	DC	GEOCH
1377.0	[m]	DC	GEOCH
1398.0	[m]	DC	GEOCH
1428.0	[m]	DC	GEOCH
1455.0	[m]	DC	GEOCH

Lithostratigraphy

Lithostratigraphy
Top depth [mMD RKB]	Lithostrat. unit
355	NORDLAND GP
650	HORDALAND GP
650	NO FORMAL NAME
703	NO FORMAL NAME
1124	ROGALAND GP
1124	BALDER FM
1205	SELE FM
1303	LISTA FM
1374	SHETLAND GP
1424	CROMER KNOLL GP
1424	RØDBY FM
1431	ÅSGARD FM
1470	VIKING GP
1470	DRAUPNE FM
1545	SOGNEFJORD FM
1665	HEATHER FM
1700	FENSFJORD FM
1848	KROSSFJORD FM

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]
227_01_WDSS_General_Information	pdf	0.16
227_02_WDSS_completion_log	pdf	0.18

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]
227_01_31_2_2_Completion_Report	pdf	5.70
227_01_31_2_2_Final_well_report_EXLOG	pdf	8.88
227_01_31_2_2_Well_summary_ANCHOR	pdf	2.76
227_02_31_2_2_Completion_log	pdf	1.32
227_02_31_2_2_Drilling_programme	pdf	2.48
227_02_31_2_2_Drilling_programme_encl_1	pdf	0.51
227_02_31_2_2_Drilling_programme_encl_2	pdf	0.17
227_02_31_2_2_Drilling_programme_encl_3	pdf	0.27
227_02_31_2_2_Drilling_programme_encl_4	pdf	0.77
227_02_31_2_2_Exploration_well_proposal	pdf	0.75
227_02_31_2_2_Exploration_well_proposal_encl_1	pdf	6.21
227_02_31_2_2_Exploration_well_proposal_encl_2	pdf	19.85
227_02_31_2_2_Exploration_well_proposal_encl_3	pdf	14.80
227_02_31_2_2_Exploration_well_proposal_encl_4	pdf	12.53
227_02_31_2_2_Exploration_well_proposal_encl_5	pdf	0.16
227_02_31_2_2_Exploration_well_proposal_encl_6	pdf	12.76
227_02_31_2_2_Exploration_well_proposal_encl_7	pdf	12.64
227_02_31_2_2_Exploration_well_proposal_encl_8	pdf	11.26
227_02_31_2_2_Exploration_well_proposal_encl_9	pdf	6.20
227_03_31_2_2_Geochemical_analysis	pdf	0.84
227_03_31_2_2_Geochemistry_evaluation_of_source_rock	pdf	0.57
227_03_31_2_2_Geochemistry_evaluation_of_source_rock_encl_1	pdf	0.07
227_04_31_2_2_Biostratigraphy	pdf	8.08
227_04_31_2_2_Biostratigraphy_appendix_3	pdf	3.79
227_05_31_2_2_Core_description	pdf	5.02
227_05_31_2_2_Core_report_core_1-13_Final_report	pdf	3.96
227_05_31_2_2_Evaluation_of_core_data	pdf	8.36
227_05_31_2_2_Geological_investigations_of_cores_vol_1	pdf	28.43
227_05_31_2_2_Geological_investigations_of_cores_vol_2	pdf	24.38
227_05_31_2_2_Geological_investigations_of_cores_vol_3	pdf	0.48
227_05_31_2_2_Sidewall_sample_description	pdf	0.70
227_05_31_2_2_Sieve_analysis	pdf	3.90
227_05_31_2_2_Source_rock_analysis_by_IKU	pdf	1.52
227_05_31_2_2_Source_rock_analysis_encl_1	pdf	0.06
227_05_31_2_2_Source_rock_analysis_encl_2	pdf	0.03
227_05_31_2_2_Source_rock_analysis_encl_3	pdf	0.02
227_05_31_2_2_Source_rock_analysis_encl_4	pdf	0.03
227_05_31_2_2_Source_rock_analysis_encl_5	pdf	0.02
227_05_31_2_2_Source_rock_analysis_encl_6	pdf	0.04
227_05_31_2_2_Special_core_analysis	pdf	2.58
227_06_31_2_2_Crude_oil_source_rock_correlation	pdf	1.22
227_06_31_2_2_Pressure_survey_report_completion_test_1_by_SPERR	pdf	0.79
227_06_31_2_2_Pressure_survey_report_completion_test_3_by_SPERR	pdf	2.78
227_06_31_2_2_Pressure_survey_report_test_1_run_1_by_SPERRY	pdf	0.09
227_06_31_2_2_Pressure_survey_report_test_1_run_1_SPERRY	pdf	0.89
227_06_31_2_2_Pressure_survey_report_test_2_run_1_by_SPERRY	pdf	1.99
227_06_31_2_2_Pressure_survey_report_test_3_run_1_by_SPERRY	pdf	0.55
227_06_31_2_2_Pressure_survey_report_test_3_run_2_by_SERRY	pdf	1.37
227_06_31_2_2_Pressure_survey_report_test_4_by_SPERRY	pdf	0.86
227_06_31_2_2_Pressure_survey_report_test_4_run_2_by_SPERRY	pdf	1.75
227_06_31_2_2_Pressure_survey_report_test_4_run_3_by_SPERRY	pdf	1.83
227_06_31_2_2_Pressure_survey_report_test_4_run_4_by_SPERRY	pdf	0.13
227_06_31_2_2_Pressure_survey_report_test_4_run_5_by_SPERRY	pdf	1.48
227_06_31_2_2_Production_test	pdf	0.30
227_06_31_2_2_Production_test_b	pdf	0.28
227_06_31_2_2_Production_test_nr1_part1_by_OTIS	pdf	7.44
227_06_31_2_2_Production_test_nr1_part2_by_OTIS	pdf	10.03
227_06_31_2_2_Production_test_nr1_part3_by_OTIS	pdf	6.68
227_06_31_2_2_Production_test_nr2_by_OTIS	pdf	11.62
227_06_31_2_2_Production_test_nr3_by_OTIS	pdf	8.95
227_06_31_2_2_Production_test_nr4_by_OTIS	pdf	8.22
227_06_31_2_2_Production_test_programme	pdf	2.42
227_06_31_2_2_Produksjonstest_nr_2_av_oljezone_by_OTIS	pdf	3.02
227_06_31_2_2_Produksjon_av_oljezonen	pdf	0.77
227_06_31_2_2_Well_test_interpretation_report	pdf	9.04
227_07_31_2_2_Reservoir_engineering	pdf	1.79
227_07_31_2_2_Reservoir_engineering_encl_1	pdf	1.33
227_07_31_2_2_Reservoir_engineering_encl_2	pdf	1.07
227_07_31_2_2_Reservoir_fluid_study	pdf	0.32
227_07_31_2_2_Reservoir_fluid_study_analysis	pdf	0.30
227_07_31_2_2_Reservoir_fluid_study_RFLA_80078A	pdf	0.70
227_07_31_2_2_True_boiling_point_distillation	pdf	0.19

Logs

Logs
Log type	Log top depth [m]	Log bottom depth [m]
CBL CCL GR	775	1825
CBL GR CCL	354	1844
FDC CNL GR CAL	430	797
FIT	1506	1506
FIT	1595	1595
HDT	1469	1855
HDT	1845	2590
ISF BHC GR SP	430	809
ISF BHC GR SP	1800	2590
LSS CTR	1845	2590
LSS GR	1469	1855
MSFL DLL SP CAL	1469	1855
RFC CNL GR CAL	1800	2590
RFT	1	0
RFT	2	8
VELOCITY	0	0

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	398.0	36	400.0	0.00	LOT
SURF.COND.	20	768.0	26	780.0	1.72	LOT
INTERM.	13 3/8	1438.0	17 1/2	1448.0	1.64	LOT
INTERM.	9 5/8	1817.0	12 1/4	1826.0	1.65	LOT
OPEN HOLE		2568.0	8 1/2	2568.0	0.00	LOT

Drilling mud

Drilling mud
Depth MD [m]	Mud weight [g/cm3]	Visc. [mPa.s]	Mud type
708	1.22	41.0	seawater
1000	1.22	49.0	seawater
1408	1.22	50.0	seawater
1624	1.26	45.0	seawater

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]
227_Formation_pressure_(Formasjonstrykk)	PDF	0.20

31/2-2