This paper discusses the urban planning process applied for field development of one of the biggest and most congested field in sultanate of Oman. The field has a carbonate reservoir contains a light oil with associated gas. The reservoir is currently under waterflood development. The oil production is co-mingled with other fields at production station and the produced water is pumped back into the reservoir for pressure maintenance and the remaining is disposed into another reservoir. The field contains an area layout of 22 km °18 km. The new development proposal of further infill drilling at a narrower spacing was challenging in term of well interference with existing infrastructure, spacing, rig movement and accessibility.
The first pass of checking the wells locations feasibility shows that only 30 percent of the wells can be drilled due to massive amount of existing wells with surface infrastructure. It was not easy to develop and drill the majority of proposed wells with required surface infrastructure. A detailed urban planning study was carried out to address the inherent issues and challenges associated with re-development of the field. An integrated multi-discipline team was formulated consisting of, Concept Engineering, Geomatics, Production Geologist, Reservoir Engineering and Well Engineering. A close coordination was also maintained with other relevant disciplines to address the surface development issues and for making the quality concept decisions in early phase of the project. The process of urban planning applied in this study was documented as a best practice within the company and cross learnings were used as basis during the study and also captured in Urban Planning Guideline which was developed internally.
Resolving the challenges for placement of wells on surface and rig accessibility for drilling challenged the normal ways of working and triggered the un-conventional thinking to establish the well drilling feasibility and integration with surface scope. Consequently, project team have come up with ways to drill the wells that would not be drilled by following the normal way of working. Integrated urban planning enabled the proposed number of wells to be drilled despite the insufficient space to accommodate standard pits and pads. In conventional approach, initial urban planning assessment concluded feasibility of drilling only 30 percent of proposed wells. However, the team managed to improve the feasibility of drilling those wells up to 90 percent. This has allowed the maturation of the planned target hydrocarbon volume and created huge value in re-development of this field. Tangible benefits also achieved in early decision-making, up to two months schedule acceleration could be realized in field development through integrated urban planning approach. Study has demonstrated that urban planning can save approximately 10 percent in off-plot CAPEX. On top of this, urban planning has helped in lowering HSE risks during the drilling and reducing production deferment during construction.