富泥型深水重力流沉积特征及沉积演化规律分析

A Study on the Sedimentary Characteristics and Evolution of Mud-rich Deepwater Turbidite Reservoir

吕文睿 曹树春 卜范青 管红 肖鹏

Lü Wenrui CAO Shuchun BU Fanqing GUAN Hong XIAO Peng

中国海洋石油国际有限公司, 北京 朝阳 100028

CNOOC International Limited, Chaoyang, Beijing 100028, China

西非盆地南部Z油田储层薄、砂地比低，属于富泥型深水重力流沉积。针对Z油田存在沉积相变快，内部水道及朵叶刻画难度大、演化规律复杂的问题，基于岩芯、测井曲线、地震剖面相及地震平面属性，结合生产动态，刻画Z油田沉积相类型、构型边界及沉积展布特征，并总结沉积演化规律。结果表明：1)研究区发育主水道、天然堤、主朵叶、朵叶侧缘、远洋泥和滑塌沉积微相。2)通过地震轴强弱变化、地震振幅属性、RGB分频融合属性刻画水道及朵叶边界。研究区发育限制性、弱限制性及非限制性水道-朵叶沉积。限制性水道以垂向叠置为主，弱限制性水道以侧向叠置为主，非限制性水道化朵叶平面展布范围广。3)研究区底部发育非限制性水道-朵叶复合沉积，以朵叶为主；向上过渡为限制性水道沉积，单期水道规模大；再向上过渡为弱限制性水道沉积，平面发育多期水道，单期水道规模小。

Located in the southern West African Basin, Z Oilfield has low net pay and low net-to-gross ratios, belonging to the mud-rich deep-water gravity-flow deposits. Based on the well penetrations, seismic attributes and production data, the facies types, sedimentary configuration boundaries of the Z Oilfield were identified. The facies distribution characteristics and sedimentary evolution of Z Oilfield were summarized, leading to the following conclusions: 1) the Z Oilfield has developed main channel, levee, main lobe, lobe fringe, shale and slump; 2) channel and lobe configuration boundaries were identified through changes in seismic axis strength, seismic amplitude attributes, and RGB frequency division attributes; 3) for Z Oilfield, the bottom oil group developed unconfined channel-lobe system, dominated by lobes, transitioning upwards to confined channel systems, with strong vertical stacking of channels, and on the top oil groups weakly confined channel systems have developed, with stronger lateral migration, and smaller scales of individual channels.

10.11885/j.issn.1674-5086.2024.09.02.01