Shaanxi Yanchang Petroleum Co Ltd (YCPC) plugged and abandoned outpost well YPT-8 in the onshore L31/50 concession, Khorat Plateau Basin, with gas shows on 13 December 2018. The well was targeting to appraise the reservoir extension of Pha Nok Khao limestone and Phu Kradung sandstones which were found to be gas-bearing in the YPT field.    Spudded on 15 August 2018, the well was drilled to a total depth (TD) of 4,009 m using Sinopec 50765 land rig. Â     The previous exploration activity was the completion of YPT-7 well on 2 January 2016. YPT-7 was the fourth well drilled in the L31/50 block following YPT-2, YPT-1 and YPT-3 wells.    The optimum location of the exploration wells may have been identified from approximately 350 sq km of 3D seismic data acquired in 2014 and 2015.     YCPC is operator and sole interest holder in the L31/50 concession.    Background Information    The L31/50 concession was awarded by Thailand Department of Mineral Fuels (DMF) to YCPC on 25 February 2010. No well had been previously drilled in the block.    YCPC commenced an exploration drilling for the first well, YPT-2, in the Chumpol Buri structure in February 2013. The well, targeting the Permian carbonates of the Pha Nok Khao Formation, was dry. YPT-1 (May-August 2013) was drilled in the Nong Khamal structure, encountered non-commercial amounts of gas in two zones within the Phu Kradung sandstones, while the Pha Nok Khao Formation was dry. The well was not tested.    YPT-3 (June-October 2013) was drilled to appraise the YPT-1 discovery, about 5 km northeast. The well encountered five gas-bearing zones in the Pha Nok Khao Formation. YPT-3 was temporarily suspended prior to flow testing. YPT-7 was spudded in August 2015, about 4 km northeast of YPT-3. The well may be possibly appraising the YPT-1 discovery.    The Permian carbonates have been the primary exploration target, but so far only two fields have been producing from the reservoir in Khorat Plateau basin. The carbonate reservoirs are associated with thrust faults that resulted in fracture development, enhancing the reservoir properties. The key of the exploration success in the Khorat Plateau is the understanding of the structural geology as well as the paleo-topography to be able to identify Permian carbonate plays with good reservoir properties.    With improved knowledge of the geology of the basin and the reprocessing of seismic data, operators should be able to limit the heavy risk associated with exploring in this basin in the past. It is prognosed that the future discoveries will be mainly gas but there may also be the potential for oil in reservoirs of the Triassic Group or Khorat Group. In the recent years DMF have tried to promote the exploration effort in the Khorat Plateau. Acreages have been offered in bid rounds and DMF have also done various studies on the Khorat Plateau's potential.
Shaanxi Yanchang Petroleum Co Ltd (YCPC) plugged and abandoned outpost well YPT-8 in the onshore L31/50 concession, Khorat Plateau Basin, with gas shows 