水下窄河道剩余油与挖潜方法

REMAINED OIL IN SUBAQUEOUS NARROW CHANNEL AND ITS FURTHER DEVELOPMENT METHOD

杏北开发区水下分流河道砂体具有窄、薄、散等地质特点，在目前井网密度条件下，采取单一技术准确刻画地下砂体难度较大，因而利用水平井挖掘河道内部剩余油也就具有一定的风险性。2009年，通过综合应用地质、测井、地震、地质建模以及数值模拟等多学科一体化技术，精细刻画了砂体展布规律和储层微构造特征，在量化剩余油分布的基础上优化了水平井布井方式及水平井轨迹。在水平井目的层构造起伏大、砂体厚度薄，横向微相变化快、河道连续性差等复杂地质条件下，实现了地质导向的准确把握。4口水平井投产后，初期平均单井13产油28t，综合含水控制在50％以下，取得了特高含水期窄河道砂体剩余油挖潜的好效果。

Subaqueous distributed channel sandbodies of Xingbei development zone are geologically featured by being nan＇ow, thin, and scattered. Under the present well spacing, it is difficult to accurately map the underground sandbodies using single technique. Consequently, it is risky to exploit the remained oil in the channels with horizontal wells. In 2009, through comprehensive application of integration of geology, logging, seismic technique, geologic modeling and numerical simulation, etc, sandbody distribution pattern and micro-structural features are finely mapped. Based on the quantization of remained oil, the well pattern and well trajectory of horizontal wells are optimized. Despite the complex geological conditions of the target formation, such as ragged structure, thin sandbody, quick change of transverse micro-facies and poor continuity of the channel, geosteering is still correctly gripped. Four horizontal wells are put into production, the average daily production per well is 28t at the primary stage, and comprehensive water cut is controlled under 5% , which is a positive result for remained oil recovery in narrow channel sandbody at super high water cut stage.