Abcreste Consulting was contracted by Talisman-Sinopec UK to undertake a review of the potential of the brown field development Tartan field located in the Outer Moray Firth, North Sea. The Tartan Field is a mature multi pay zone oil field development that has been in production since 1978 using a dilapidated platform in dire need of refurbishment

• Review the existing field data
• Revise the geological& simulation fieldmodels
• Identify future development& near field options
• Identify gas source for gas lift purposes
• Review the facilities integrity, upgrade evaluation
• Identify the LTRO on the main Tartan field

Abcreste Consulting ’s work resulted in full field evaluation that identified a series of opportunities for future growth and also the risks associated with such opportunities. Talisman acquired a fully comprehensive field review that was long overdue and provided the basis for it to decide on a desired future course of action.

Review the regional geology and tectonic evolution

Revisit all core data (56 wells), sedimentological, sequence strat & facies model incorporated into the reservoir model

Generated a paleogeographicmap for entire area

Review and reinterpret the existing seismic data (Abcreste Consulting seismic interpretation specialist)

Review and define the hydrocarbon contacts and reservoir parameters

Update volumetric analyses

Identify infill drilling opportunities

Populate well hopper

Identify work over opportunities

Identify secondary recovery options

Compile a prospect inventory with associated chance of success analysis

Review and verify the production data

Generate forward production estimates for existing and potential new well locations

Identify options for nearby gas resources for gas lift required for Tartan re-start

Assess the facilities status and impact on future development options

Review operating costs and identify cost reduction opportunities

Undertake economic analysis

Provide a series of recommendations to the operator

Abcreste Consulting ’ consultant was involved in the field review and development planning of the York gas field. The York gas field is located in the Southern North Sea (SNS) area of the United Kingdom Continental Shelf (UKCS). Presence of many intra-faults , particularly the intra-fault located south-west of the field makes the development of the field challenging.

• Review available field data
• Review existing development plan
• Build a new dynamic model
• Identify development options
• Recommend optimal development plan

Provided the company with two optimal development options and a flow chart showing the dependence of option two on optionone Operator drilled wells in the field based on work carried out and FDP submitted by Abcreste Consulting ’ Consultant The operator put the field to production with production within prognosedrates

Review available Reservoir Engineering data

Liaise with in-house G&G and Petrophysics discipline staff towards ensuring dynamic considerations were reflected in the static model build

Build dynamic model

Investigate different development well types

Identify optimal number of wells for developing the field

Generate production profile for the field based on identified development options

Undertake economic analysis

Recommend optimal development options for the field

VJN Engineering Consultancy UK Limited, along with LR Senergy was contracted by an Oil & Gas Producing Company operating in Caspian Sea to investigate the potential for water hammer effect emanating from abrupt valve closure during water injection. The study also evaluated the potential for sand production in producer wells along with determining minimum flowrates for optimal production with minimal solids production and transportation.

• Determine maximum pressure pulse for varying valve closure times.
• Provide input to geo-mechanics for formation fracture analysis.
• Determine sand transportation and bedding pattern.

The study performed by VJN & LR Senergy has resulted in identifying possible sand deposition locations essential for pigging operation. Best practises for valve closure have also been advised. The study also provided an avenue for a subsurface/subsea multi-disciplinary collaboration, where expertise from both fields provided the client with an optimumsolution.

Reviewed the production profiles (oil, water, gas and solids productionrates).

Determined study basis to best simulate various life of field operating conditions of the asset.

Built OLGA models of both production and injection wells.

Simulated and evaluated water hammer effect in injection wells.

Simulated and evaluated sand production and deposition during production.

Identified areas of sand bedding in pipeline.

Identified sand accumulation rates topsides

Determined maximum attenuation expected for various valve closures times

Advised optimum valve shutting time to minimise risk of water hammer and formation damage.

Assessed the topsides facilities capacity and impact of sand production on future tie-back options

Generated a technical report detailing findings of the study.

Provided recommendations relating to optimising production whilst limiting sand production.

Abcreste Consulting ’ was mandated by Sonangol to carry out an independent review on the economic feasibility in doing a Cross Block Development between2 Ultradeep offshore blocks (blk 16 &3 1). The York gas field is located in the Southern North Sea (SNS) area of the United Kingdom Continental Shelf (UKCS). Presence of many intra-faults , particularly the intra-fault located south-west of the field makes the development of the field challenging.

• Quick screening for compatibility of all Blk 31 SE & Blk 16 fields
• Validate and Re-evaluate reserves, by providing ZAIL independent view
• Phased drilling by rigorous well optimisation (location, timing and count)
• Facilities flexibility and scalability
• Economics- Reducing upfront CAPEX, maximising facilities Ullage, maintaining production plateau as long as possible

Provided the company with an optimal phased development option, delaying upfront CAPEX by $700m and CAPEX savings up to $2 billion Study results proved that development could break even atmuch loweroil prices (<$30/bbl savings) Sonangol was more informed in reviewing IOC’s request to adjust PSC terms to favour their blk 31 and blk 16 standalonedevelopment concepts A more detailed FDP was initiated amongst the contractor group as a result of ZAIL study

Data review and update

Fluid compatibility (PVT), DST’s, Geology e.t.c

Model review and update

Network model review and update

Volumetrics, production rates and production profiles (P10,P50 & P90)

Economic models Development concept (Facilities)

Desktop study of existing documentation and review analogue developments

Prepare design study basis and agree report format

Identify design cases based on P10, P50, P90 resource and production

Identify feasible concepts including options and sub-options

Determine engineering quantities for conceptual reference case

Preliminary safety and environmental considerations

Preliminary risk, reliability and availability considerations

Development schedule

CAPEX and OPEX estimates

Economic evaluation

PA Resources (PA) engaged Abcreste Consulting to support its Tunisia offshore permit Farm-Out process. Abcreste Consulting consultant provided technical, strategic and commercial support working alongside both the PA team and external advisors.

• Engage a financially strong and competent technical partner to technically participate alongside PA in the operation and development of both permits.
• Cover a portion of the cost of on-going exploration and development funding via cash and development carry.

Abcreste Consulting assisted PA in attracting a high quality licence partner and in achieving financial and contractual terms for the sale which compared favourably with recent benchmark deals in Tunisia. PA announced its successful farm-out of the Didon and Zarat offshore permits in Tunisia on 29 May 2013. The divestment related to the transfer of a 70% share in each permit and operatorship of both permits to Enquest. The Zarat permit contains the undeveloped Zarat and Elyssa fields and a number of exploration targets, whilst the Didon permit contains the producing Didon Field. The terms of the sale were:
• An upfront cash consideration of USD 23 million;
• Additional cash payment of USD 93 million contingent on development of the Zarat field; and
• Contingent payments of up to USD 133 million following successful project developments upon achieving certain targets.

Participated in a peer review of the draft plan of development to identify and resolve gaps in advance of launching the farm-out process.

Developed sales materials including the information memorandum & management presentation in association with PA staff.

Sourced an appropriate data room provider and prepared a virtual data room in support of the marketing of the assets.

Provided strategic and commercial advice during the negotiation of the sale to Enquest. This included advice on negotiation tactics, commercial review of terms and input to the Sale & Purchase Agreement.