PetroChina â Changqing achieved progress in shale oil exploration in the Ordos Basin. Chengye 1 and Chengye 2, two horizontal exploration wells, tested 886 b/d (121.38 t/d) and 791 b/d (108.38 t/d) of oil respectively from an oil-shale interval in the Chang 7 Unit (Yanchang 7 Unit) of the Upper Triassic Yanchange Formation after fracking. Chengye 1, a new-pool well, was spudded on 7 April 2019. The both wells, targeting the shale interval in the Yanchang Formation, were drilled in the Chenghao oil field which is located in the Yishan Slope of the basin.  In the past few years, PetroChina - Changqing made great effort on shale oil exploration in the Ordos Basin.   A giant shale oil field, Qingcheng field, was approved in the Ordos Basin in September 2019. Qingcheng Field, located in the southwest of the basin, has been approved 358 million tons (2.5 bn bbl) of oil in place in the Triassic Chang 7 Formation, with 693 million tons (4.9 bn bbl) of P3 oil in place, which indicated a 1 bn tons (7 bn bbls) scale field discovery.   The Qingcheng field has been on development and it was expected to be produced at a rate of 12,800 b/d of oil in 2019. The field was also expected to reach a production of 60,000 b/d of oil in the next few years.   Another shale oil field, Xin'anbian shale oil field, was reported to be the first shale oil field (initially was classified as tight oil) found in China to surpass 100 million tons (over 700 MMbbl) of proven oil in-place.   The Xin'anbian shale oil field was discovered in 2007 when An 83 penetrated 17.5 m oil pay in the Chang 7 Unit of the Yanchang Formation, later on the well tested 12 t/d of commercial oil. This is the first time that commercial oil flow was obtained from the shale interval in the Xin'anbian area, it is also China's first giant shale oil field.   Background Information  The Ordos Basin is the important oil and gas production base for PetroChina, in particularly on unconventional, such as tight gas, tight oil and shale oil. In 2018 PetroChina produced total 23.6 million tons of oil and 38.7 Bcm of gas, the company has target to produce 24 million tons of oil and 42 Bcm of gas in 2020, 28 million tons of oil and 45 Bcm of gas in 2025.   The Yanchang 7 Unit is the main source rocks in the Ordos Basin. Since 2011, PetroChina has started exploration for shale oil in the Chang 7 Unit. In 2014 the company confirmed Xinâanbian shale oil field with approved 700 MMb of oil in place.   The Yanchang Formation is the most favorable oil-generating source rocks in the Ordos Basin, dominated with lacustrine mudstones and thin siltstones. Dark mudstones of the Yanchang Formation are as thick as 300 m to 400 m with an area of 80,000 sq km. The best source rock is within the Yanchang 7 Unit, single layer thickness of mudstones ranges from 5 m to 25 m, total thickness of mudstones ranges from 10 m to 50 m, maximum can be great than 80 m. The source intervals of the Yanchang 7 Unit have a TOC content ranging from 2% to 5%, bitumen A from 0.3% to 0.5%, and total hydrocarbon value of 1833 ppm to 3503 ppm.
Chengye 1 & 2 expl Horiz shale wells in the Chenghao oilfield, Yishan Slope, both fracked and tested resp. 886 bo/d + 791 bo/d from the Chang 7 Unit (Yanchang 7 Unit), Yanchange fm.