The field X is a brown heavy oil field producing under strong bottom water drive since the mid-1980. Production is from a combination of Amin aeolian and Al Khlata glacial reservoir sediments. At present, the development is focused on drilling horizontal infill wells. One of the biggest challenges is the unfavorable mobility contrast between the heavy oil and water causing early water breakthrough.
The Amin Formation, the primary reservoir, is characterized by a high net to gross ratio and an average porosity of 30 %. However the initial hydrocarbon saturation at the same porosity often varies by 20 % in different parts of the field. Furthermore, core measurements show an order of magnitude scatter in permeability at the same porosity, indicating the presence of different facies. In early studies these variations were attributed mainly to the grain size variations. A later petrographical study found that the abundance of clays and feldspars could also severely reduce permeability, but may retain high porosity.
In the current Study it was found that the rocks have variable radioactivity due to the presence of radioactive Potassium isotope associated with feldspars. A fare correlation was observed between the grain size and the content of feldspars from core. A novel approach to reservoir characterization integrating core and logs was developed leading to a major breakthrough in the reservoir characterization including:
• Enhanced permeability prediction using normalized Gamma Ray (GR) log as 3rd parameter;
• Facies identification using normalized Gamma Ray cut-off;
• Facies based Saturation-Height models.
This work is a good example of advances in reservoir characterization achieved by integrating core and log data. It results in better understanding of reservoir properties distribution, optimization of completions of new wells and improvement of further development scenarios. In particular, abnormally high gross production and high water cut in the north of the field is currently in line with new facies scheme.
Wu, JinYong (Schlumberger) | Banerjee, Raj (Schlumberger) | Bolanos, Nelson (Schlumberger) | Alvi, Amanullah (Schlumberger) | Tilke, Peter Gerhard (Schlumberger - Doll Research) | Jilani, Syed Zeeshan (Schlumberger Oilfield UK Plc) | Bogush, Alexander (Schlumberger)
Assessing the waterflood, monitoring the fluids front, and enhancing sweep with the uncertainty of multiple geological realisations, data quality, and measurement presents an ongoing challenge. Defining sweet spots and optimal candidate well locations in a well-developed large field presents an additional challenge for reservoir management. A case study is presented that highlights the approach to this cycle of time-lapse monitoring, acquisition, analysis and planning in delivery of an optimal field development strategy using multi-constrained optimisation combined with fast semi-analytical and numerical simulators.
The multi-constrained optimiser is used in conjunction with different semi-analytical and simulation tools (streamlines, traditional simulators, and new high-powered simulation tools able to manage huge, multi-million-cell-field models) and rapidly predicts optimal well placement locations with inclusion of anti-collision in the presence of the reservoir uncertainties. The case study evaluates proposed field development strategies using the automated multivariable optimisation of well locations, trajectories, completion locations, and flow rates in the presence of existing wells and production history, geological parameters and reservoir engineering constraints, subsurface uncertainty, capex and opex costs, risk tolerance, and drilling sequence.
This optimisation is fast and allows for quick evaluation of multiple strategies to decipher an optimal development plan. Optimisers are a key technology facilitating simulation workflows, since there is no ‘one-approach-fits-all' when optimising oilfield development. Driven by different objective functions (net present value (NPV), return on investment (ROI), or production totals) the case study highlights the challenges, the best practices, and the advantages of an integrated approach in developing an optimal development plan for a brownfield.
Ahmad, Khalid (Kuwait Oil Company) | Ferdous, Hasan (Kuwait Oil Company) | Llerena, Javier (Kuwait Oil Company) | Ahmad, Fatma (Kuwait Oil Company) | Chaudhary, Pradeep (Kuwait Oil Company) | Abbas, Faisal (Kuwait Oil Company) | Sammak, Ibrahim (Kuwait Oil Company)
One pilot study presently being conducted through CSS thermal recovery technology to explore a shallow poorly-consolidated viscous oil bearing sandstone reservoir in Kuwait with extensive integrated reservoir evaluation efforts to optimize the future development strategy.
The reservoir largely consists of two separate deltaic sand packages representing multi-stacked channel facies resulting to stratified reservoir intervals with variable degree of fluid saturations. Reservoir characterization uncovers high matrix contents along with calcite, dolomite, and clays as cements which essentially control uneven pore-geometry that fabricate the petrofacies types into multiple thin stratified-pay intervals, each being < 30' thick with variable fluid saturations resulting from long transitional thief zones posing high risk for thermal recovery. Thus, a seemingly simple channel-based reservoir interval has been greatly altered by diagenetic episodes that need evaluation towards an arduous perforation, completion and production strategy to pursuit the well-defined individual thin pay-interval.
Single-well thermal recovery scheme under "injection-soak-production?? sequence being conducted presently in three vertical wells, each subjected to first cycle injection of moderate quality steam (~75% at 4200 F) at rates 400 to 600 barrels EW/d at about 450 psig injection pressure for 26 to 71 days, followed by a soak period of 10 to 60 days. Subsequent total production estimates SOR between 0.2 and 0.9. In two wells, cumulative oil/water productions and 15% to 34% water cut indicate an excellent response to thermal stimulation. The encouraging injection parameters of steam slug size, high injection rates at low pressures, and subsequent productions provide valuable information towards upcoming second cycle injection and future steam flood strategy.
The ongoing CSS pilot is providing some critical information for the future commercial development phase. As such, all pertinent data are closely evaluated to ensuring the optimal strategy to meet the long-term development plan for this viscous oil asset.
Both oil and gold are commodities with price in US Dollars, but they choose different path in trend figure. While gold has been showing great stability over the years, oil keeps changing in price level. Oil price movements have distorted measurement of economic variables measured in dollar values. In economical evaluation for oil and gas field development projects longer than one year, oil price is one of the most critical assumptions.
This paper is trying to solve whether:
• gold is more stable than US dollars or other currencies
• gold equivalency is more reliable way to project the future costs/price
• the gold-based oil price can be applied in current economical evaluation template for justification of approval process on field development plan
Considering crude oil prices are moving dynamically for last decade, this paper exercise the model to determine realistic oil price assumption by using more stable "currencies??, thus it can provide more reliable and accurate economical evaluation. It shows that gold-based inflation-adjusted crude-oil price is preferable indampening or mitigating:
• effect of dynamic oil price nature
• impact of inflation
• risks of paper-based currency fluctuation
• discount rate requirement
Using case study of Indonesian Production Sharing Contract (PSC) fiscal terms, gold-based oil price provides more simple economical evaluation, resulting real net cashflow of field development plan. The paper concludes by demonstrating using gold equivalency instead of paper-based currencies provides more consistent and reliable nominal revenue in both perspective of PSC Contractor and Government.
Fan, Zifei (Petrochina Research Institute of Petroleum Exploration and Development) | Yang, Xuanyu (China University of Petroleum) | Xue, Xia (China National Oil and Gas Exploration and Development Corporation) | Xu, An Zhu (PetroChina E&P Co) | He, Ling (Petrochina Research Institute of Petroleum Exploration and Development) | Zhao, Lun (Petrochina Research Institute of Petroleum Exploration and Development) | Mu, Longxin (Petrochina Research Institute of Petroleum Exploration and Development)
The well patterns and pattern types of well placement issue in a productive formation is an important aspect of the effective field development. The problem solution is impossible on the intuitive level due to the reservoir inhomogeneity. At present the well pattern is accepted to be located basing on the famous criteria, specialist experience and hydrodynamical simulation on a reservoir model. The designer should analyze many field development variants with different well spacing during limited time interval. The adjustment of large-scale multiwell field-development projects is challenging because the number of adjustment variables and the size of the search space can become excessive. This difficulty can be circumvented by considering well patterns and then optimizing parameters associated with pattern type and geometry. In this paper, we introduce a new framework for accomplishing this type of adjustment for vertical two or three reservoirs.The development of vertical multiple reservoirs were usually by a separate well pattern for every reservoir, or through reservoir-by-reservoir from bottom to top by only one well pattern. A separate well pattern for every reservoir requires drilling many more wells and higher investment costs, while development through reservoir-by-reservoir from bottom to top by one well pattern made oil recovery rate and development efficiency very low and uneconomic. Consideration on fully developing every reservoir well efficiently, firstly, an inverted-nine well pattern was designed for every reservoir and the well space was L (L was defined as an optimal well space for respective reservoir) and the distance between adjacent well patterns was L. Secondly, all wells were drilled to the bottom of the lowest reservoir. Thirdly, when average water-cut of producers in every two well patterns was greater than 80%, the two well patterns interchanged reservoirs. Finally, when all reservoir interchange was completed, every reservoir was developed by the new equivalent infilled well pattern with well space of L. The adjustment strategy made the required number of drilling wells in the whole field can be reduced by 50% and achieved better development effect. This strategy was put into practice on North Buzachi oil field in Kazakhstan and average oil rate of single well was increased by 20%, oil recovery rate has an increment by 12 percent, the recovery factor was increased by 6.7%, economic profit is 1.8 times that of one separate well pattern for every reservoir, the effect was perfect. This work analyzed the performance of this new strategy of well pattern design and adjustment to effectively develop vertical multiple series of reservoirs and the methods to determine the reasonable time of two well patterns interchanging reservoirs through simulation study and current application effects.
The extreme conditions and harsh environment for which FPSO's andhydrocarbon gathering facilities are being considered introduces distinctchallenges to effective and efficient project management and execution. The presentation is based on the experiences gathered during the design phasesof two contemporary harsh environment FPSO's and the associated subsea,flowline, pipeline and riser systems (Chevron Rosebank and GAZPROMShtokman). This presentation will focus on the adjustments that must beconsidered to "standard" project execution and management in order toincorporate the elemental distinctions without sacrificing efficiency, logicalsequencing, safety or project schedule. Specifically, the presentationwill focus on the following:
The paper is intended to inform the audience as to the distinctivecharacteristics of harsh environment design management contrasted with the morefamiliar benign environment design projects.
The subject Gas Field is located in the Sulaiman Fold Belt (SFB) in Pakistan. A realistic 3D static model was constructed for the challenging multiple reservoirs in the Field which included both clastics and carbonates. Four main reservoir horizons were modeled.
The steps involved in the Reservoir engineering analyses were: analyze PVT, well test, Static Pressure Data, and Core. The static pressure analysis helped define hydraulic compartmentalization in the field.
WHFP measurements were not available in the desired accuracy and density. A surface network model was used with plant inlet pressure as the primary constraint in order to obtain the required information. Satellite based elevation information was used to establish an accurate model with respect to pressure drop due to liquid hold up in pipelines.
The History Match in the field was performed on a Zone by Zone basis. In the absence of a 3D seismic cube, many of the faults in the field could not be interpreted, yet their presence was predicted by a closely matching Sand Box Model. This was an important clue which led to a useful approach regarding the location of simulation faults distributed in the entire field. An innovative approach was used in order to calibrate the size of sand lenses in one of the zones.
The final step was the forecasting and development of Optimal Scenario using Economic analysis. Many scenarios were tested, and the optimal scenario was identified. Maximum use was made of existing wellbores through re-completion, and new drilling was minimized. Furthermore, the impact of increasing the currently low Gas Price was tested. It was concluded that doubling of the gas price of the field would increase the NPV 3 times delay abandonment by 6 years.
The Gas Field is located in the Sulaiman Fold Belt (SFB). Eighteen (18) wells in all, those have been drilled in the Field. Currently 12 wells are producing Gas. The primary target horizons in Field are the Sui Main Limestone (SML) and Lower Ranikot (LRKT). However, the Dunghun Limestone and Pab Sandstone are also producing in some of the wells. The depositional sequence consists of clastic and carbonate succession. The stratigraphy of the reservoirs is strongly influenced by the structural evolution of the Sulaiman Fold Belt and initial rifting of the Indian Plate.
The hunt for further oil and gas recovery from old wells isbooming, and the industry look to new and improved technology for addingseveral years of operational time to exicting wells. New methods like lightwell intervention procedures sets high stress on old wellheads andinfrastructure, and a general increase in development of marginal fields haveraised issues over safety aspects.
Aside from developing improved procedures around cementingoperations, leakage detection and oil spill recovery, additional successfactors will be the ability to monitor pressure and temperature fluctuations inB annulus, as well as finding models and produce technology to manage suchpressure build upsuccessfully.
This paper introduces a new method of B-annulus monitoring using ultrasoundsignals originating from a device in the A-annulus providing measurements basedon time of flight in chambers placed in the B-annulus as a means of determiningthe temperature and pressure in the B-annulus.
Industrial benefits planning (IBP) can greatly assist oil companies inseeking to access or operate in frontier regions, including the Arctic. Anumber of ‘good practice' approaches in the design and implementation ofsuccessful benefits plans have emerged. There is a general need for initiativesin such areas as supplier development, procurement/contracting, education,training and hiring. However, these initiatives, and an IBP program as a whole,will be most effective if the following approaches are adopted: cooperation,collaboration and education; building on existing strengths and capabilities;and seeking a diversified and more sustainable economy.
The Hebron Benefits Plan provides a recent and often innovative example ofpetroleum industry benefits planning. Of particular interest is the emphasis itplaces on: the role of contractors and suppliers, leaving a lasting legacy, andcooperation and collaboration with other stakeholders. In a further benefitsplanning innovation, ExxonMobil Canada Properties states that it will establishand maintain a ‘benefits culture,' based on the well-established model ofsafety culture, within its organization and all Hebron contracting companies.The Plan presents policies, guidelines and procedures with respect to supplierdevelopment, contracting and procurement, employment and training, research anddevelopment (R&D), diversity, and monitoring and reporting.
Recent initiatives in Greenland illustrate the challenges faced inimplementing more limited benefits initiatives in an Arctic and near-Arcticenvironment. Cairn exploration programs have had Government of Greenlandmandated benefits plans and agreements that have delivered both employment andbusiness to Greenland residents and companies. They have also put in place newinfrastructure, for example related to weather forecasting and oil spillcontingency equipment. However, not all of the employment, business andinfrastructure initiatives have delivered the desired effects.
Newfoundland and Labrador, Canada, is an example of a jurisdiction where,facilitated by well-established IBP processes, the offshore petroleum industryhas delivered substantial and sustainable economic development. This is partlya result of the creation of a new offshore petroleum sector of the economy thatprovides employment and business and makes a major contribution to theProvince's GDP and tax base. Newfoundland and Labrador also now has anexpanding university sector, large numbers of university graduates, a small butthriving R&D community, an increasingly diverse and cosmopolitan urbanculture, and improved external transportation links, all of which can be atleast partly attributed to the oil industry.
TOTAL Exploration & Production has been active in cold environmentssince 1970 (i.e. drilling in the Arctic Islands in Canada) and has beenoperating the Russian Kharyaga field since 1999. For its first experiences inthose challenging conditions, TOTAL applied its internal rules andspecifications that were not aimed at this kind of environments but to"classic" prospects, the main assets being in the Guinea Golf, in the NorthSea, the Middle East and in South East Asia. As the prospects and TOTAL'sportfolio have developed in areas where temperatures are below -15°C, such asKashagan field in Kazakhstan or Yamal in Russia, an "Extreme Cold" taskforcewas put together several years ago. The aim is to gather feedbacks from thepast and to centralize the Research & Development activities to look forinnovative solutions for the future and on-going projects. The workgroup isorganized around several panels, one of those being the Health and Safetyaspects for the operations in Extreme Cold conditions. From partnership throughJIPs, internal research and workshops with affiliates (mainly in Norway, Russiaor Canada), and projects teams, it has been decided to produce internalguidelines in order to define and harmonize the practices, acknowledging thateach field has its own meteorological constraints, and to gather the resultsfrom the multiple actions carried out by TOTAL headquarters or affiliates. Themethodology and the risk analysis performed to obtain a common technical basiswill be here presented.