This article reports on the results of a survey distributed in April 2007 to government special education schools and settings throughout Australia. The survey collected information about the age and special education qualifications of teaching staff. It followed a similar survey that was distributed in May 2006 to Victorian special schools that found that 44.9% of teachers and principals were aged 50 years or more, and 68.9% had a special education qualification. In the current survey, the percentage of principals and teachers aged 50 years or more in the responding schools ranged from 37.5% in New South Wales to 51.0% in the Australian Capital Territory. The percentage of special education qualified staff varied from 53.1% in the Australian Capital Territory to 86.6% in Western Australia. These results are examined in further detail and possible implications discussed.

This work is done in the context of a giant carbonate reservoir with 40 years of production/injection history. In this reservoir, the key heterogeneities that impact the production mechanisms (high permeability streaks, permeability contrast, intra dense and dual sub-zones of varying maturity) are well characterized, through major field reviews. However, in the recent years, unexpected high water saturation were encountered while drilling infill horizontal drains. An integrated multi-scale investigation was conducted to understand the potential mechanism of water movement within the lower sub-zone through an assimilation and interpretation of data and multi-disciplinary understanding. This work resulted in further optimization of remaining infill wells and the field development strategy. The observed high water saturation signatures were investigated through integration and analysis of multi-disciplinary data, using data acquired in infill wells during the last three (3) years. First, the studied wells were categorized primarily based on their water cut, water saturation encountered and then mapped along with their data. Second, the different scenarios of possible water movement were developed chronologically. Third, a multi-scale integrated analysis (well level to reservoir level) and subsequent mapping was captured on a montage. The developed scenarios were validated with recent surveillance, monitoring data and corroborated with geological/geophysical understanding. This comprehensive approach and results were corroborated with blind tests in terms of the dynamic behavior of the water. Faults and their characteristics were identified as a key element affecting this local dynamic behavior. Saturation logs showed high water saturation but were inconclusive on whether this water is mobile or not. This required integration with dynamic flow data from production logging and well tests. The dynamic data was integrated with the seismic and geological findings to ascertain whether the water presence is due to poor rock type, water migration through faults or water movement in the matrix. The findings were mapped and led to re-consider the well placements and expectations from infill wells while crossing faults. This enhancement of the reservoir understanding resulted in mitigation of risks in future producers which subsequently impacted the reservoir development strategy. This multi-scale analysis over the reservoir provided an insight into the source of the unexpected high water saturation in the undrained lower sub-zones of the reservoir. Thus, revising the understanding of the field development strategy, well placement and related contingencies.

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Carbonates are infamous for their complex intrinsic heterogeneity, exaggerated due to stratification and layered geology. Characterization and correlation of this heterogeneity with recovery mechanisms becomes critical pertaining to Lower Cretaceous reservoir ‘A’ with over 4 decades of production/injection history. Hence, it is pertinent to systematically reduce the uncertainties associated with reservoir characterization by delineating high permeability streaks, permeability-contrasts, links between geological and petrophysical facies and their impact on field scale production/injection strategies. Emphasis was put on capturing downhole dynamic Kv/Kh profile across sub layers of the reservoir ‘A’, to enable assignment of representative values into reservoir simulation model with associated reservoir zonation. Vertical interference testing (VIT) was designed in a crestal location well with a history of near-by waterflooding, integrating simulator-based outputs with petrophysical and borehole image logs of an offset. Drawdown-buildup cycle was performed across source probe or packer, while simultaneous monitoring of pressure at observation probe. To reduce uncertainty and incorporate statistical sense into the data, multiple cycles of drawdown-buildup were conducted for vertical connectivity evaluation. In total, eleven VIT tests conducted with formation tester tool utilizing dual-straddle-packer and two-probe modules were interpreted implementing a systematic approach considering vertical communication as a function of geological facies and textural aspects from borehole images, geological information on fractures/faults, and surfaces. Interpretation involves identification of flow-units based on available logs, followed by identification of flow regimes (spherical/radial) to history-match data for estimation of horizontal and vertical permeabilities of each layer. Resultant analysis yielded insights on anisotropy by validating vertical communication through stylolite and across dense layers. Integration of VIT analysis results (Kh,Kv,Kv/Kh) with petrophysical logs led to the establishment of water flood advancement mechanism in this observation well at the crestal location of field. This establishes a critical link between integrated geological, textural and facies analysis in context of sedimentology, layering and rock quantified fabric permeability indicators visible on high vertical and horizontal resolution borehole image. Thereby, allowing derivation of scalable answer products and workflows. Subsequently, explaining water flood mechanism and enabling updating of simulation model for enhanced reservoir characterization. Furthermore, this also allows for field development augmentation and injection strategy optimization through linking of dynamic results to reservoir description of two major sub-layers of this giant carbonate field. Integration and analysis of key insights on vertical communication and carbonate anisotropy with major geological/petrophysical features aided in characterizing 3D static and dynamic models. This would allow improved trajectory planning of future wells, leading to improvement in recovery efficiency through guided injection strategy. Additionally, proactive data aggregation and insightful interpretation to help accelerate realization of value from field development strategy was highlighted.

Carbonate reservoirs are generally highly heterogeneous and complex because many phenomena, such as diagenesis and tectonism have modified primary depositional structure and texture. Many carbonate reservoirs in the Shuaiba Formation of north Oman are characteristically heterogeneous with complex reservoir architecture. It is common to observe dual-media and natural fracture system behaviors with large variations in reservoir properties. Many of these reservoirs have been developed with horizontal wells, so they require application of advanced reservoir evaluation and management practices. Many of the horizontal wells produce at high water cuts, despite apparent initial high oil saturations. The need for data is paramount for effective management of these reservoirs, and to understand factors affecting the productivity of horizontal wells - both at the wellbore and within the reservoir itself. The first stage of this process is to define an accurate structural model incorporating all available reservoir, wellbore (2D modeling) and seismic data. The second stage, involves integrating this model with the inflow profile derived from advanced production logging measurements. We describe several field examples from a complex and heterogeneous carbonate reservoir in Oman, and discuss how they may be used to identify a range of important needs relating to horizontal well placement, improving completion strategy, and optimizing water shut-off activities. Introduction Short to long radius horizontal wells have been drilled in many types of oil and gas reservoirs, in both carbonate and siliclastic formations. A variety of technical advances in drilling, including logging while drilling and formation evaluation have meant that the application of horizontal wells for reservoir development in both primary recovery and enhanced oil recovery (EOR) applications is now a common practice. There are many options available for completion of horizontal wells, such as open hole (barefoot), cased hole (e.g. cemented, expandable and perforated liner), slotted liners and gravel-pack completions. In the Middle East and North America a large proportion of horizontal wells have openhole completions. Since horizontal wells have a much greater reservoir contact area than vertical wells, for reservoirs with lateral heterogeneity, fault and fracture networks or structural compartmentalisation, this can result in well performances that range from the spectacular to the very mediocre.