The characteristics of sedimentary composition and evolution models of the Miocene reef are studied by combining the latest drilling data and seismic data. The reef-building organisms in the studied area are mainly calcareous alga, followed by hexacorallia; and accessory reef organisms mainly consist of the foraminifera and ostracod. According to the development of reef-building organism rocks which can be divided into reef skeleton-framestone and non-reef skeleton-framestone, the former includes red coral and reef framework dolomite and red algal-halimedadolomite, and the non-reef skeleton-framestone mainly consists of bioclastic limestone, grain of marl and packstone. The sedimentary facies include reef framework, reef flat, lagoon, backreef bank and bioclastic facies. The sedimentary evolution of Miocene organic reef follows the rising of the relative sea level, then a set of aggradation-retrogradation reef sedimentary cycles. The reef development can be mainly divided into four stages:the foundation, initial prosperity, peak and expose recession. During the fourth stage for reef and development, the favorable reservoir in studied area was formed by extensive dolomitization of exposure shoals.

reef  /  skeleton-framestone  /  reef-building model  /  sedimentary composition  /  Miocene  /  Xisha waters