大民屯凹陷隐蔽油气藏资料处理技术研究

Processing of seismic data over the subtle reservoirs in Damintun depression.

辽河盆地大民屯凹陷的勘探目标已由构造油气藏转向隐蔽性较强的地层油气藏和岩性油气藏。根据大民屯凹陷资料特点,开展了隐蔽油气藏配套处理技术研究。针对凹陷中央部位研究了叠前零相位处理技术、时空变谱拓展技术及to道拟合技术,有效地提高了地震资料的纵向分辨率,沙三段和沙四段主频达到45-50 Hz,能够识别15-20 m的薄砂层。针对大民屯凹陷东、西陡坡带以及基底潜山开发研究的叠前时间偏移技术,提高了地震资料的横向分辨率,改善了潜山的成像精度。所研究的技术推广应用到大民屯荣胜堡-前进地区和静北地区990 km2范围的实际生产中,有效地提高了勘探基础资料的品质。应用新的处理成果,大民屯凹陷在低潜山勘探和沙三段岩性油气藏勘探两大领域取得了突破,部署了多口预探井。

The exploration targets in Damintun depression, Liaohe Basin have changed from structural reservoirs into more complicated subtle ones such as stratigraphic and lithological reservoirs. We developed a suite of techniques for the processing of seismic data from Damintun depression. For the center of the depression, the key techniques includes prestack zero-phrase processing technique, space-time variant spectrum spread technique, t0 trace fitting technique. The dominate frequencies for S3 and S4 strata on the resulted sections are up to 45 - 50 Hz, and thin sand layers with thickness of 15 - 20 meters can be recognized. For the east/west sides and bottom buried-hills, we use prestack time migration technique as the key to improve lateral resolution of seismic data and imaging precision of bottom buried-hills. The proposed techniques have also been applied to the processing of 3-D seismic data from Qianjin and Jingbei survey areas (covering an area of 990 km2) in the de pressioa Based on the new data, several wells have been deployed and breakthroughs have been made in the fields of lower burred-hills and S3 lithologic reservoirs.