构造+岩性油气藏地震处理、解释一体化实例研究

构造+岩性油气藏正逐步成为油气藏勘探重要目标之一,构造+岩性油气藏的主要特点是构造简单,储层岩性复杂。构造+岩性油气藏勘探的主要难点是如何提高储层构造解释精度和储层沉积解释精度以及相应的速度求取精度和地震分辨能力。针对以上问题,基于珠江口盆地番禺油田开展了构造+岩性油气藏的地震勘探方法研究。研究区存在海底和第四系厚度变化较大、长波长空间变速、气云、地震分辨率、构造精度和储层沉积解释精度等问题。多次波压制、相对保持提高分辨率、高精度地震速度求取、储层构造等时格架解释、储层沉积演化与砂体构型解释,以及井震地质构造成图等是解决构造+岩性油气藏勘探问题的关键技术。后期开发井验证表明,对于研究区埋深约3000m的储层,通过以上精细处理和解释一体化系列技术,其构造+岩性的储层地震勘探精度可以达到千分之一的精度范围。

Integrated seismic processing and interpretation for a structural+stratigraphic reservoir: a case study

Structural and stratigraphic reservoirs characterized by simple structure and complex lithology are becoming major targets for oil and gas exploration. The difficulties of this kind of reservoirs in exploration are the accuracy of the structural and depositional interpretation of the reservoir, the accuracy in velocity estimation as well as seismic resolution limitation. To deal with these problems, a seismic exploration study for a structural and stratigraphic reservoir in PY Oilfiled, Zhujiankou Basin is carried out. The main problems for PY Oilfield are such as abrupt change of water depth and Quaternary system depth, spatial variation of the velocity field, imaging in gas cloud area, seismic resolution, as well as accuracy of structural and depositional interpretation. The study proves that: multiple attenuation, resolution enhancement with relative amplitude reserved, high precision velocity estimation, isochronous structural framework interpretation, depositional evolution and architecture of sand bodies interpretation, as well as structure mapping with integration of seismic and well logging are critical techniques in structural and stratigraphic reservoir exploration. Lately drilled development wells in the oilfield verify that the depth error of the interpretation is less than 0.1 % for target reservoirs at 3000 m depth.