LF 21-4-1 was completed in late September 2019 without result reported.  CNOOC â Shenzhen spudded a NFW in the PRMB Basin, South China Sea, on 16 August 2019. LF 21-4-1, located in the Lufeng Sag in a water depth of 300 m area, has target in the Mio-Oligocene clastic play. âNanhai 6â S/S is used of the drilling operation.   In 2019, CNOOC has completed LF 16-7-1, LF 7-10-1d and LF 15-8-1 in the Lufeng Sag without result reported.   Around this area, several wells have been drilling, LF 8-1-1, LF 14-4-1 and LF 14-8-1 have been reported as discovery well, but another few wells, such as LF 9-2-1, LF 9-6-1, LF 14-2-1, LF 14-3-1 and LF 15-2-1 are not success.  CNOOC made discovery of LF 8-1-1 and LF 14-4-1 in 2014.LF 14-4-1 penetrated about 150 m of oil pay and tested 1,320 b/d of oil from the Lower Tertiary Zhuhai Formation.   In 2015, CNOOC drilled an appraisal well, LF 14-4-2, and reported as a success oil well.   In 2017 CNOOC drilled appraisal well, LF 8-1-2 to assess LF 8-1-1 discovery.   In 2017 CNOOC made discovery in LF 14-8-1 and tested oil from the Oligocene Enping Formation.   In addition, in 2018, SK Innovation made LF 12-3-1 discovery. The well was drilled to a TD of 2,014 m and encountered 34.8 m net oil pay. Test rates from the well was up to 3,750 bo/d from the Lower Miocene Zhujiang Formation.  Background Information    There are several fields on production in the Lufeng Sag:     LF 7-2 field is operated by Newfield and it was on stream in 2014. The field is producing from the Zhujiang reservoir at a rate of 23,500 b/d of oil in 2016.   LF 13-2 field, operated by CNOOC, also has reservoir in the Zhujiang Formation and on stream in 2006. It is produced at a rate of 6,400 b/d of oil in 2016.   LF 13-1 field has primary reservoir in the Zhujiang Formation and secondary one in the Oligocene Enping Formation. The field has been producing since 1993 and produced 16,000 b/d of oil in 2016.   LF 22-1 field - The field was officially shut down in June 2009 after nearly 12 years production as the field depletion.  In 2019, CNOOC is preparing to launch a new overall development plan for Lufeng oil fields cluster in the South China Sea oil fields cluster.  The Lufeng oil fields cluster, including Lufeng 14-4/14-8/8-1, Lufeng 15-1 and Lufeng 22-1, lies in the east or southeast part of the existing Lufeng oil fields group Lufeng 7-2 and Lufeng 13-1 fields. The Lufeng 22-1 field SPS will be connected to the drilling/production platform in the Lufeng 15-1 field via a 19 km of pipeline. A drilling/production platform will be built in the Lufeng 14-4 field and linked with the platform in the Lufeng 15-1 field via a 23.8 km pipeline.
LF 21-4-1 was completed in late September 2019 without result reported.