Division of “layer exploration unit” and high-efficiency exploration in mature exploration area

Abstract

Abstract: To realize high-efficiency and sustainable exploration of the Jiyang depression at the stage of high exploration degree, a hydrocarbon accumulation-geological evaluation method is developed on the basis of current geologic knowledge and extent of fine exploration. The concept of “layer exploration unit” is proposed in the study, and it is defined as an exploration geological unit that has a relatively complete and unified tectonic system, sedimentary system and hydrocarbon migration & accumulation system in a tectonic layer or tectonic sublayer within a fault basin. Then, an approach to dividing and evaluating the “layer exploration unit” is developed. With this approach, the Jiyang depression is divided into 305 layer exploration units, thus helping realize precise and stereoscopic geological understanding and exploration deployment. Fine splitting of remaining resources and benefit evaluation of exploration targets are conducted by “layer exploration units”. As a result, 66 efficient “layer exploration units” in four major areas (i.e. Paleogene upper Es4−Dongying Formation, Neogene Minghuazhen Formation−Guantao Formation, Paleozoic buried-hill, and Paleogene Kongdian Formation−lower Es4) are determined as the targets for obtaining more reserves and breakthroughs in the short and medium term. Key words: Bohai Bay Basin, Jiyang depression, fault basin, mature exploration area, layer exploration unit, fine exploration, high-efficiency exploration