| Popis: |
Located in offshore South China, Panyu oil field has entered into mature development phase after a decade of intensive production. A new horizontal wells campaign has resumed since 2012 targeting the remaining thin oil column reserves that are being squeezed by strong bottom water drive. The fluid contacts are highly uncertain in the current reservoir state. After a review of the technical and geological challenges encountered during the project, this paper will feature the successful approach taken to optimize remaining reserve recovery using innovative horizontal well placement strategies. The how-to-execute of these strategies will be detailed through the description of various cases encountered. This includes landing the wells with very low incident angle - less than 2 deg at the top of the reservoir - and drilling the lateral sections within a very small target window (2 ft) below the reservoir top, which both require rigorous geological well placement and control. In addition, the authors will describe how during the thorough planning phase, the team has selected to use directional electromagnetic and wellbore imaging technologies for proper well placement, reservoir profiles description, and current OWC level identification.The team has observed that the application of these integrated strategies and technology solutions have helped to:Eliminate the needs for pilot-hole wells and contributed to the improvement of the drilling efficiency by keeping the trajectory within the reservoir, avoid unnecessary adjustments, and avoid the sidetracks, thus significantly save the AFE budget. Minimize attic oil, thus optimizing the remaining reserve recovery. Optimize the outline of future horizontal drains locations.The performance of the horizontal wells drilled up to date – and placed extremely close to the reservoir top – shows that each of them has produced from 2000 to 6000 bopd with zero to very low water cut. A reversing production trend from the decline to positive growth is also recorded. Six months after the first horizontal well inception in September 2012, the cumulative incremental oil of the field has reached 2.1 million barrels or 45% higher than forecast. The successful implementation of the new development strategy and the application of fit for purpose technologies in highly mature oil fields have led to sustained and extended production, increasing the ultimate recovery and asset economics. |
