特低丰度油藏水平井开发技术研究与应用

有效动用外围储量是大庆油田实现产量接替的关键之一，为此开展了大庆外围油田的特低丰度超薄（厚度不足1m）葡萄花油层水平井开发试验。采用地震解释系统和地质建模技术，精细解释拟布水平井井区葡萄花油层的构造和断层，并优选基于目标的砂体模拟地质统计学方法进行岩性插值，为水平井单井设计及地质导向提供依据；通过数值模拟，优化选择了水平井采油直井注采行列井网，并进行了产能预测。实时获取钻井过程中的电测数据及井眼轨迹数据，实现随钻电测数据曲线的实时显示及地质模型的及时修正，指导钻头在砂体内部钻进方向。通过岩屑和气测录井，对储集层的含油性进行评价，为地质导向及后期射孔提供保障。实测超薄油层阶梯状水平井含油砂岩钻遇率平均为55％，最高超过75％。已投产6month以上的10口水平井平均单井初期产油量为19．5t／d，单井稳定产油量为8．9t／d，皆为直井的3倍以上，开发试验取得了成功。图1表2参18

Technique of exceptionally low abundance oil reservoir development by horizontal wells and its application

A horizontal well development test of exceptionally low abundance formations was conducted in the Daqing Oilfield. The formations are thinner than lm. The seismic interpreting and geologic modeling were utilized to describe the structure and faults of the formation where the horizontal wells were to he located. The target-based geological statistics method of sandhody modeling was selected for lithology interpolation and providing foundations for the design and geological guide of horizontal wells. The well network with producing horizontal wells and both injecting and producing vertical wells was selected as the optimal well network, and the production capacity was forecasted by simulation. The electric test and well track were obtained and imaged at real time. The geological model was modified also at real time and used to guide the drilling direction in the sand. The sand oiliness was estimated by the drilling returns analysis and gas logging, providing the basis for geological guide and later perforation. The actual average sand ratio drilled along horizontal well bores is 55%, with the highest ratio of 75%. The average stable production rate of the 10 horizontal wells which have been producing for over 6 months is 8.9t/d per well. The average initial production rate of the 10 horizontal wells is 19.5 t/d per well. They are three times more than those of vertical wells.