Microsoft Word - M060 - Well Completion Report.doc · Web view2021. 3. 15. · Arrow Energy NL...

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MORANBAH GAS PROJECTPL191 M060

Comprised of:M060V

M060GMA

M060GMB

Bowen Basin, Queensland

Level 13, AMP Place, 10 Eagle St Brisbane Qld 4000Telephone: 07 3105 3400Facsimile: 07 3105 3401Email: [email protected] Website: www.arrowenergy.com.au

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Contents Page

M060V....................................................................................................................................... 1

M060GMA.................................................................................................................................. 1

M060GMB.................................................................................................................................. 1

Contents Page................................................................................................................................ 2

Introduction..................................................................................................................................... 4

Location..................................................................................................................................... 4

Purpose..................................................................................................................................... 4

Design........................................................................................................................................ 4

Well Summary................................................................................................................................. 5

Maps............................................................................................................................................... 6

Geology........................................................................................................................................... 8

Regional Geology...................................................................................................................... 8

Local Geology and Stratigraphy.................................................................................................9

Q-seam............................................................................................................................... 11

P-seam............................................................................................................................... 11

P-Tuff.................................................................................................................................. 11

Goonyella Middle (GM-seam).............................................................................................11

Goonyella Middle Lower (GML-seam)................................................................................11

Drilling........................................................................................................................................... 12

Drilling Technique.................................................................................................................... 12

Vertical Well Design................................................................................................................. 12

Lateral Well Design.................................................................................................................. 16

Lateral Well Cards..............................................................................................................17

Drilling Summary........................................................................................................................... 27

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GM010v......................................................................................Error! Bookmark not defined.

GM010a.....................................................................................Error! Bookmark not defined.

GM010b.....................................................................................Error! Bookmark not defined.

Appendix....................................................................................................................................... 28

Appendix B – Production casing designs.................................................................................29

Appendix C – Lateral casing designs.......................................................................................30

Appendix E – Daily Drilling Reports.........................................................................................31

Arrow Energy NL – Moranbah Gas Project – Well Completion

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IntroductionLocationThe ‘Moranbah Gas Project’ (MGP) is situated on the eastern flank of the township of Moranbah, two hours west of Mackay and within the ‘Bowen Basin’, Central Queensland. The project commenced development in August 2003 and is comprised of the two petroleum leases PL191 & PL196.

PurposeCoal Bed Methane (CBM) Production Well targeting the Goonyella coal seam(s).

DesignThe vertical production well, is intersected by lateral wells. These lateral wells are produced using directional drilling techniques. (Appendix A - for a description of the various types of lateral well designs used within the ‘Moranbah Gas Project’).


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Well SummaryPetroleum Lease PL191Well Name M060

Comprised of M060VM060GMA M060GMB

Well Design ChevronTarget Seam(s) GMSpud Date 01/05/2007Release Date 18/08/2007


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Maps

Figure 1 : Location of the Moranbah Gas Project (MGP) in Central Queensland


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Figure 2: Location of well group in relation to the petroleum leases

Triassic Mimosa Group

Late Permian Blackwater Group

Middle PermianBack Creek Group

Moolayember Formation Clematis Sandstone Rewan Formation Rangal Coal Measures Burngrove Formation Fairhill Formation

MacMillan Formation German Creek FormationIngelara Formation

Moolayember Formation Clematis Sandstone Rewan Formation Rangal Coal Measures Fort Cooper Coal MeasuresMoranbah Coal Measures

Blenheim Formation

AgeFormationSouthNorth


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GeologyRegional GeologyThe ‘Moranbah Gas Project’ (MGP), comprised of PL191 and PL196 (Figure1), is located on the north-western flank of the Permo-Triassic ‘Bowen Basin’.

The Bowen Basin was formed in three distinct phases over the Early-Palaeozoic metamorphic and sedimentary strata of the ‘Drummond Basin’ and ‘Anakie Block’.

Commencing in the Early-Permian, a period of extension produced a series of isolated fault- bounded basins. In the case of the Bowen Basin, subsequent partial filling occurred in the form of volcanic (e.g. Lizzie Creek Formation) and sedimentary, Group I, (e.g. Reids Dome Beds) deposits. Secondly, after the period of rifting had ceased, thermal relaxation caused further subsidence allowed for further deposition. This second phase, or Group II deposits, lasting until the Late-Permian, was dominated by a series of marine deposits including the ‘Back Creek Group’ and ‘Tiverton Formation’. The final phase in the formation of the Bowen Basin was produced by the subsequent overtaking of the thermal relaxation by foreland loading. This transition occurred as progressive, Group III, deposits were laid down under conditions which varied from the marine-influenced deltaic environment of the German Creek Formation, to the dominantly fluvial flood plain environments of the Moranbah Coal Measures.

Coal accumulations occur throughout the 3 phases and large volumes of ‘Coal Bed Methane’ (CBM) are known to be held within the Permian coals in the north of the basin. A period of contraction in the Middle to Late-Triassic terminated any further sedimentation within the basin.

Dominating the north of the Bowen Basin are two north-south trending depositional centres, the ‘Denison Trough’ to the west and the ‘Taroom Trough’ to the east. The ‘Moranbah Gas Project’ is positioned upon the ‘Collinsville Shelf’, a stable tectonic easterly dipping environment situated on the western flank of the ‘Taroom Trough’.

The area is mantled by an irregular cover of poorly consolidated Tertiary sedimentary strata and basalt (fresh and weathered) of the Suttor Formation. The Tertiary cover overlies the sediments and main coal-bearing units of the Late Permian Blackwater Group (Table 1). The Blackwater Group is divided into three terrestrial units, namely the Moranbah, Fort Cooper and Rangal Coal Measures (MCM, FCCM and RCM).

Table 1 - Regional Stratigraphic Nomenclature of the Bowen Basin


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Local Geology and StratigraphyThe ‘Moranbah Coal Measures’ form part of the Late-Permian ‘Group III’ coals deposited in the third and final phase of the formation of the Bowen Basin. ‘Group III’ coals deposited on the ‘Collinsville Shelf’ vary from the marine-influenced deltaic environment of the German Creek Formation in the south to the dominantly fluvial, flood plain environment of the Moranbah Coal Measures in the North. Most of the high grade coking deposits mined in Queensland is sourced from the ‘Group III’ coals from the ‘Collinsville Shelf’.

Nearby volcanic activity, in the form of Tuffaceous bands, is evident throughout the ‘Blackwater Group’. Within the ‘Blackwater Group’ there is a marked increasing in the number and regularity of these tuff bands as one passes from the ‘Moranbah Coal Measures’ and into the ‘Fort Coopers Coal Measures’. With their distinct gamma response these tuffs act as useful markers.

The ‘Moranbah Coal Measures’ are the main target for coal seam gas production within the ‘Moranbah Gas Project’. They consist of coals, sandstones, siltstones and mudstones and average from 250m to 300m in thickness.

The ‘Moranbah Coal Measures’ are characterised by several laterally persistent, relatively thick coal seams interspersed with several thin minor seams. Four of these seams are considered as viable seam gas targets these are, from top to bottom; the Q, P, GM and GML seams. The seams generally strike Northwest-Southeast and dip uniformly to the east between 3 and 5, although localised areas of steeper dip may occur in association with structural features.


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Figure 3: Outline of the stratigraphy of the Moranbah Coal Measures

Conformably overlying the ‘Moranbah Coal Measures’ are the ‘Fort Cooper Coal Measures’ (FCCM) which are approximately 400m in thickness. Along with coal seams sediments they include sandstones, siltstones and mudstones. The ‘Fort Coopers Coal Measures’ are characterised by up to seven coal seams varying in thickness from 6m to 60m. The coal seams are distinguished by their high inherent ash content and abundant associated tuffaceous beds. Despite the seam’s low gross to net coal ratio and poor permeability the FCCM represent a potential gas resource.

The Rangal Coal Measures (RCM) conformably overlies the FCCM and are targeted elsewhere by Arrow Energy as a potential gas resource. The RCM are typically 150 m thick with two main coal seams ranging in thickness from 3 to 9m.


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Target Seams Of The Moranbah Coal MeasuresWithin the ‘Moranbah Coal Measures’, their are currently 4 coal seams from which Coal Bed Methane is either being produced from or are under investigation as potential target seams.

Q-seamThroughout the lease the Q-seam is split into three main plies, the QA1 (3.5m), QA2 (3m) and the QB (1.75m). Northeast ward of the town of Moranbah the QA seam thickens as it deepens. The QA ply is currently being tested for suitability as a target seam of the future.

P-seamAfter the GM-seam the P-seam is the second most targeted source of Coal Seam Methane within the ‘Moranbah Gas Project’. Formed of 3 plies, the GR (3m), PL1 (1.5m) and PL2(0.5m), the P- seam averages about 5m in thickness and is rich in tuff bands. North of latitude 757000 the seam starts to split and by 758000 is measured at about 25m in thickness from the roof of the GR to the floor of PL2. Currently none of the plies are categorised as target seams but investigation into the GR has shown some promising results.

P-TuffThis is a regionally extensive marker bed, below the P-seam and above the GM-seam, and is an important unit for correlation due to its characteristically high natural gamma signature.

Goonyella Middle (GM-seam)Currently the primary target seam within the ‘Moranbah Gas Project’. The seam averages 5m in thickness but thins towards the southeast as a result of seam splitting. In the lower half of the seam are two tuff bands, the Penny and Tonstein bands, these, when drilling the laterals, act as useful marker in avoiding floor touches.

Goonyella Middle Lower (GML-seam)Like the QA seam, the GML-seam is currently being tested for suitability as a target seam of the future. On average the seam is 6.5m thick and in the south is found 40 to 50 meters below the GM seam. Evidence suggests that this inter-burden, between the GM and GML seam is relatively rich in small, thin plies of coals and carbonaceous mudstones.


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DrillingDrilling TechniqueThe directional drilling technique employed by Arrow Energy involves two distinct phases. Firstly a vertical well is drilled which intersects the target coal seam(s). Secondly a series of lateral in- seam holes are drilled which intersect the vertical well. The in-seam holes provide a clear path for water to be pumped out via the vertical well and for gas to travel to the surface.

A number of well designs are employed throughout the field. The choice of well design at each location being governed by a number of factors including the presence of known or suspected fault(s), a significant or severe roll(s) within the area to be drilled, coal permeability, and cost.

The predominant design used within the MGP is the ‘chevron’. The angle of separation between the two ‘wings’ is typically set at 50 . This creates an evenly spaced, relatively dense, pattern of clear pathways through the coal whilst allowing for a reduced number of vertical wells from which to draw off the ‘Coal Bed Methane’.

Vertical Well DesignVertical wells are built in a number of stages. Initially a large diameter hole is drilled out and short length of large diameter steel ‘Conductor Casing’ is concreted in. This is followed by the drilling out and setting of a tertiary section of steel casing. This ‘Tertiary Casing’ is set roughly 6m beyond the Tertiary sediments into the well consolidated Permian deposits.

Thirdly, the cement within the ‘Tertiary Casing’ is drilled out and a hole drilled to 50m below the deepest target seam. The added depth below the target seam is designed to act as a sump. The sump collects fines that are created by the process of pumping water out of the producing well and minimising the need for excessive workovers during the wells lifespan.

Once drilled the hole is wireline logged using a minimum of ‘Gamma’, ‘Long & short spaced density’ & ‘verticality’. The resultant LAS file provides a record of the wells path away from the vertical as well as accurate picks of the target coal seam(s).

Using the LAS file results the well is cased. The plan, for this, the ‘Production Casing’, has a number of different solutions (Appendix B). Next and again using the LAS file result, the target coal seam(s) is under-reamed providing a broader area for the lateral drilled wells to target.Lastly, the well is flushed of cuttings opening it up and clearing the well of debris.

Later, once the rig has moved of the drill site, the under-reamed section(s) is wireline logged using a 3-arm calliper. The process is designed to record how successful the under-reaming process was and defines the size and shape of the area to be targeted by the lateral well.


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Vertical Well Card


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Vertical Well Schematic


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Vertical Well Density & Gamma


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Lateral Well DesignLateral wells are also built in multiple stages. Starting on a pre-determined mast inclination and azimuth, like the vertical well a large diameter hole is drilled out and short length of large diameter steel ‘Conductor Casing’ is concreted in. This too is followed by the drilling out and setting of a tertiary section of steel casing and like the vertical well, the lateral wells ‘Tertiary Casing’ is set roughly 6m beyond the Tertiary sediments into the consolidated Permian deposits.

Once the cement for the ‘Tertiary Casing’ has cured it is drilled out and a narrow gauge casing liner is installed. The casing liner is installed in order to maintain the high ‘up hole velocity’ of the drilling fluids and their cuttings during the next stage of the drilling of the radius bend.

Next, the radius bend is drilled out using directional drilling equipment. Like the ‘Casing Plan' of the vertical well, a range of radius bend solutions are employed within the ‘Moranbah Gas Project’. The choice of solution is determined by factors such as the target seam and the competency of the inter-burden, (see Appendix C). Upon completion of the radius bend, to a predetermined position, the directional drilling equipment is pulled out of the hole and a ‘Hole Opener’ is used to expand the diameter of the hole in preparation for the ‘Radius Bend Casing’. The ‘Radius Bend Casing’, like the ‘Production Casing’ of the vertical well is run into and cemented into position. The well is now prepared for the final stage of the process, ‘In-seam drilling’.

The same directional drilling equipment is loaded into the hole and using a mixture of ‘slides’ and rotary drilling a path is drilled from the base of the radius bend into the target coal seam and along to the target vertical well. Depending on factors such as geology the in-seam section may deviate from path. In such a case the drill string is pulled back and a lip cut is drilled, branching off and back towards the under-reamed section of the lateral well.

Lastly, once an intersection with the vertical well has been achieved the drill string and BHA are removed and a polyethylene liner is run from surface of the lateral to its intersection with the vertical.


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Lateral Well Cards


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Lateral Well Schematic


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Verified Survey Report


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Drilling SummaryM060VThe well was drilled without incidence.

M060GMaThe well was drilled without incidence.

M060GMbThe well was drilled without incidence.


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AppendixAppendix A - Diagram of lateral well designs.

Lateral well design applied: Chevron

Single Lateral

Chevron Boat SingleLateral

Herring Bone

Single Lateral

Branching


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Appendix B – Production casing designsThere are 4 vertical casing strategies applied within the MGP. These are;

P vertical – the well is drilled to just above the GM-seam roof and cased to within 400mm of the P-seam roof.

GM vertical – the well is drilled to 50m below the GM-seam floor (often through the GML) and cased within 400mm of the GM-seam roof.

o The casing closest to the seam is fibreglass, reducing the chance of leaving steel in coal.

Milled out P in GM vertical - the well is drilled to 50m below the GM-seam floor (often through the GML) and cased within 400mm of the GM-seam roof.

o The casing through the P-seam is fibreglass or steel and is milled out after the casing is cemented into position.

o The casing closest to the GM seam is fibreglass, reducing the chance of leaving steel in coal.

P & GM vertical open between target seams - the well is drilled to 50m below the GM- seam floor (often through the GML) and cased within 400mm of the P-seam roof.

o The inter-burden between P & GM-seam is determined as competent enough to remain open without casing.

Casing plan applied: GM vertical


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seam.

GM-seam radius bends - fibreglass into seamSteel casing is set to just above the GM seam with a fibreglass leader into the seam.

GM-seam radius bendsSteel casing is set to just below the P

Appendix C – Lateral casing designsThere are 3 radius bend casing strategies applied within the MGP. These are;

P-seam radius bendsSteel casing is set to either just above or just within the P-seam.


Appendix E – Daily Drilling ReportsOn agreement with the DNRM the ‘Daily Drilling Reports’ are not attached as they have already been submitted to '[email protected]'.

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