济阳坳陷中生界古潜山油气富集规律及有利勘探区预测

在济阳坳陷中生界古潜山油气储集系统、构造对油气成藏的控制作用等分析基础上,对油气富集规律分析认为,古潜山圈闭油气富集高产必须邻近古近系生油凹陷且位于油气运移通道系统之上、发育构造裂缝及次生孔隙的砂砾岩或火山岩储集系统、具有古近系的区域性披盖层;综合生、储、盖和构造条件分析,对中生界古潜山油藏有利勘探区带进行了预测,对下一步深层油气勘探具有一定的指导意义。

MQ地区断层封闭性模糊综合评判

运用模糊综合评判方法分别对MQ地区NEE、NNW、EW等3种走向断层的封闭性进行了定量评价。自沙一段沉积期(油气最早充注期)以来,不同走向的断层封闭性存在很大的差异。NEE向断层侧向封闭性差,以侧向输导作用为主;NNW向断层在其后的不同地质时期内封闭性不同,整体表现为封闭、开启相互交替的特点;EW向断层具有封闭特征,在局部地区与NNW断层形成断层遮挡油气藏,分析结果与实际勘探状况基本一致。

Sequence boundaries and regularities in the oil-gas distribution of the low swelling slope belt in the continental rift basin

Where are the zones more enriched in sand deposits in the down slope and deep depression of the low swelling slope belt? Are there any screening conditions for oil and gas there? These are the chief geological problems to be solved during exploration of a region. Taking the Paleogene system developed along the east slope belt of Chengdao as an example the concepts of sequence stratigraphy and sedimentary sequenc are applied. A new research method likened to a way ''to get a melon by following the vine'' is proposed to determine the direction for exploring within un-drilled or less-drilled areas. This is the process: ''the characteristics of the sequence boundary ? the forming mechanism of the stratigraphic sequence ? the conditions of oil and gas accumulation ? the distribution zones of oil and gas''. The relationship between the dynamic mechanism of stratigraphic sequence and the forming conditions for oil and gas accumulation establishes that the tectonic disturbance of the slope belt has significant responses as denudation and deposition. Above the stratigraphic sequence boundary there are large scale sand bodies of the low stand system tract (LST) that have developed in the low swelling slope belt and its deep depression. Below the sequence boundary there are the remaining sand bodies of the high stand system tract (HST). On the slope there is a convergence of mudstone layers of the extended system tract (EST) with the mudstone of the underlying strata, which constitutes the screening conditions for the reservoir of the down slope and deep depression. The distribution regularities in preferred sand bodies on the surface of the sequence boundary, and in the system tract, indicate the ordering of oil-gas deposits. From the higher stand down to the depth of the slope there are, in order, areas where exploration was unfavorable, major areas of stratigraphic overlap of oil-gas reservoirs, unconformity screened oil-gas reservoirs, and, finally, sandstone lens oil-gas reservoirs. The low swelling slope belt of Chengdao was tectonically active, which is typical for a continental rift basin. The methodology and results of the present paper are significant for the theory and practice of predicting subtle reservoir and selecting strategic areas for exploration.

Geological factors associated with unsuccessful exploration wells in the northern margin of the Qaidam basin

We investigated the geological factors associated with unsuccessful exploration wells in the northern margin of the Qaidam basin to better understand their cause.The structural situation,the hydrocarbon accumulation mechanism and unsuccessful well data collected from 1996 to 2005 were studied.The results show that the main geological factors associated with unsuccessful exploration wells are a lack of effective source rocks and a lack of effective traps,as well as the migration-accumulation conditions that exist in this area.The basin was reformed by Meso-Cenozoic tectonic evolution.Multi-stage tectonic activities have both positive and negative effects on hydrocarbon accumulation.Source rocks distribution,effective migration channels,effective traps and the tectonic evolution effects on hydrocarbons should be the key objects for further studies.

Physical simulation of hydrodynamic conditions in high rank coalbed methane reservoir formation

In order to select highly productive and enriched areas of high rank coalbed methane reservoirs, based on hydrologic geology as one of the main factors controlling coalbed methane （CBM） reservoir formations, the effect of hydrodynamic forces controlling CBM reservoir formations was studied by a physical simulation experiment in which we used CBM reservoir simulation facilities. The hydrodynamic conditions of high coal rank reservoirs in the Qinshui basin were analyzed. Our experiment shows the following results： under strong hydrodynamic alternating action, 6C~ of coalbed methane reservoir changed from the start at -2.95% ~ -3.66%, and the lightening process occurred in phases; the CI-I4 volume reduced from 96.35% to 12.42%; the CO2 vo- lume decreased from 0.75% in sample 1 to 0.68% in sample 2, then rose to 1.13% in sample 3; the N2 volume changed from 2.9% in sample 1 to 86.45% in sample 3. On one hand, these changes show the complexity of CBM reservoir formation; on the other hand, they indicate that strong hydrodynamic actions have an unfavorable impact on CBM reservoir formation. It was found that the gas volume and hydrodynamic intensity were negatively correlated and low hydrodynamic flow conditions might result in highly productive and enriched areas of high rank CBM.

Quantitative research method for tectonization intensity:a case study in Tahe-Lunnan oilfield of Xinjiang

The research on tectonization intensity plays an important role in the analyses of basin evolution and hydrocarbon accumulation. At present, methods in this field are almost qualitative, and the quantitative one is still rarely reported. In this study, a quantitative research method for tectonization intensity is proposed. The research result on Tahe-Lunnan oilfield shows that this method can not only quantitatively express the tectonization intensity, but also qualitatively reflect the macroscopic deform property and the evolution history of strata. Therefore, it is an effective method for analyzing the characteristics of tectonization. In addition, the realization of the method also can provide qualitative information for studying the influence and control of tectonization on hydrocarbon accumulation.

关于油田寿命的思考

一个油气藏从油气生成到消亡的进程,与其所经历的地质历史、地质作用和人工开采因素有关。人工开采加快油气藏消亡的进程,开发方式和技术手段不同会影响油田的开发生命周期。通过不断创新应用方法和技术,增加地质储量和可采储量,可有效延长油田的开发生命周期。根据大庆油田萨北开发区不同开发阶段的特点和矛盾,以提高油田采出程度为主线,论述了以早期注水、分层开采、加密调整为主的二次采油技术和以聚合物驱、三元复合驱为主的三次采油技术以及以自适应驱油体系为主的化学驱后四次采油技术对延长萨北开发区开发生命周期的开发实践。未来勘探开发技术水平的不断提高,将增加油田地质储量和可采储量,基于翁氏预测模型和偏正态分布数学模型,预计萨北开发区可以开采至2110年以后。