摘要
土库曼斯坦阿姆河右岸基尔桑地区的天然气藏发育在上侏罗统牛津阶生物礁灰岩中,为弄清其礁储层发育的控制因素,进行了岩石学特征、储层物性特征、储集空间特征、储层纵横向分布特征等储层特征分析。结果表明:礁灰岩储集空间主要是溶孔、溶洞和裂缝;储层物性为中孔低渗,非均质性强;气藏储集层类型以裂缝—孔隙型为主,局部发育裂缝—孔洞型;纵向上储层主要发育在XVhp、XVa1层;平面上储层主要分布在东北部Gir22—Gir2井一带。在此基础上,确定了礁储层发育的控制因素:①沉积相控制礁体分布,确定了储层整体格局;②溶蚀作用改善了储层品质,进而控制了优质储层的分布;③构造裂缝是储集体高产富集的重要因素。最后提出:基尔桑地区丰富的油气资源证实深水斜坡上也可能发育有利的礁滩储层,该认识对于国内"优质碳酸盐岩礁滩储层基本发育于台地边缘"的观点有较大突破。
Gas reservoirs are developed in the Upper Triassic Oxfordian biohermal limestone in the Girsan area of Amu Darya Right Bank, Turkmenistan. In order to understand the main factors controlling the formation of the reservoirs, we studied their petrologi- cal characteristics, physical properties, reservoir space, and vertical ~ lateral distributions. The following results were obtained. The reservoir space of the biohermal reservoirs are dominated by dissolution pores, caverns and fractures. The porosity is moderate, the permeability is low, and the heterogeneity is strong. The reservoirs are mainly fractured-porous types, with fractured-vuggy res ervoirs occurring locally. Vertically, the reservoirs are mainly developed in the XVhp and XVal intervals. While laterally, they are mainly distributed along the Gir22 - Gir2 well block in the northeastern part. The major factors controlling the development of the biohermal reservoirs were also identified, a. Sedimentary facies controls the distribution of biohermal complex, thus defines the over- all pattern of reservoir distribution, b. Dissolution improves reservoir quality, thus it controls the distribution of quality reservoirs. c. Tectoclase is an important factor controlling the productivity of reservoirs. Based on the fact that petroleum resources are rich in the Girsan area, it is suggested that quality reef-shoal reservoirs may also be developed on deep slopes. This is a breakthrough in the previous understanding in China that quality ree^shoal reservoirs are mostly developed on platform margins.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2013年第3期10-14,共5页
Natural Gas Industry
