东海深井高温高压低孔渗储层钻井技术研究与应用

随着近年东海勘探工作量的迅速增加,钻井深度越来越深,面临着深层高温高压低孔渗地层钻井的一些重大技术难题.针对遇到的难题,分析研究了钻井技术和工艺,主要包括深部复杂压力体系井身结构优化、构建储层保护和井壁稳定性能良好的低自由水钻井液体系、高压低孔渗储层防气窜固井工艺技术、分井段钻井提速配套技术.研究成果应用表明,该套技术较好地解决了钻井过程中出现的问题,保护了储层,提高了时效,满足了产能测试的要求.     

锦州25—1区块探井钻井实践与认识

锦州25—1油田是渤海湾近年钻探发现的大型油田。锦州25—1区块先后钻了十多口探井,在钻井作业中遇到上部井眼扩大严重、井径不规则、井垮、起下钻遏阻卡、电测作业遏阻、电测井底沉砂较多、井漏等复杂情况。通过对锦州25—1区块前面几口探井钻井中出现的问题进行认真分析,研究了锦州25—1区块的地层压力剖面分布。经过不断的总结与措施改进后,在后面的探井钻井作业中做到了起下钻顺利,上部井径扩大率较小,未出现井垮情况,电测一次到底,钻井作业生产时间大幅度提高,为锦州25—1油田的生产井钻井积累了宝贵的经验。     

Development of A Depth-Integrated Longshore Current Model with Unstructured Grids

A depth-integrated model for simulating wave-induced longshore current was developed with unstructured grids. Effects of surface roller and horizontal mixing under combined waves and currents were incorporated in the numerical model. Recommended values of model coefficients were also proposed based on sensitivity analysis. Field observations and three series of laboratory measurements including two cases conducted on the plane beach and one implemented on the ideal inlet were employed to examine the predictive capability of this model. For the field case and laboratory cases conducted on the plane beach, numerical results were compared favorably with the measured data. For the case with an ideal inlet, simulated circulation pattern is supposed to be reasonable although some deviations between numerical results and measured data still can be detected.     

Rotation Center and Horizontal Bearing Capacity of the Bucket Foundation in Soft Ground

In the last 20 years, the bucket foundation has been developed as a new type of offshore platform structure. Because of its short period of application to engineering practices, the theoretical decision on the rotation center and horizontal bearing capacity of the bucket foundation has yet to be agreed. A limit analysis method is used to determine the updated rotation center position and horizontal bearing capacity to evaluate the failure mechanisms of the bucket foundations. The results are compared with numerical simulation and experiments, and also with other theoretical methods. The proposed method can satisfactorily consider the engineering conditions and the result is accurate in determining the rotation center and horizontal bearing capacity.     

Jellyfish patch formation investigated by aerial photography and drifter experiment

Jellyfish patch formation is investigated by conducting a drifter experiment combined with aerial photography of a sustained patch of the moon jellyfish in Hokezu Bay, Japan. Jellyfish patches are aggregations of individuals that are caused by a combination of swimming (active influence) and advection by currents (passive influence). The drifter experiment involved the injection of 49 drifters around a distinct surface patch of jellyfish within an area of approximately 300 m × 300 m. The drifters’ motion, caused only by the passive influence, was recorded in a series of 38 aerial photographs taken over approximately 1 h. The ambient uniform current field larger than the patch scale was estimated from the movement of the centroid position of drifters, while the distribution of horizontal divergence and relative vorticity around the patch was estimated from the time-derivative in areas of triangles formed by the drifters. The centroid positions of both drifters and patches moved stably toward the bay head at different speeds. The difference vector between the patch and drifter centroids was directed to the sun, and was opposite to the ambient current. The distributions of vorticity and divergence around patches exhibited inhomogeneity within the patch scale, and the drifters in this nonuniform current field aggregated near the convergence area within 1 h. The results suggest that horizontal patch formation is predominantly influenced by passive factors at the surface of Hokezu Bay. Furthermore, the upward swimming against downwelling may make sustained patch in surface layer.     

岷县漳县6.6级地震极震区峰值加速度估算

简述了2013年7月22日岷县漳县6.6级地震极震区破坏特;针对调查中发现的砖柱铁门地震破坏现象,应用力学分析原理估算了极震区地震水平峰值加速度。估算结果表明,极震区禾驮乡拉路村地震水平峰值加速度在5.1～5.4m/s2,即0.52～0.55g左右,大于《中国地震烈度表》Ⅷ度区参考的水平向地震峰值加速度,这可能与研究区黄土及山坡的双重放大效应有关。因此在灾后恢复重建及该区未来的抗震设防中应考虑这两方面的作用影响。     

测井资料Xu-White模型预测横波速度的一些新观点

目前横波预测的方法大致可以分为两种:经验公式预测和理论岩石物理模型。由于经验公式预测一般具有区域性,研究者更重视岩石物理模型预测。目前大多数岩石物理模型预测横波的方法假定地下流体的物性参数(速度和密度)不受地层深度的影响,且孔隙扁率是恒定的,实际上这并不科学。因为矿物的体积模量和剪切模量随所处地层深度发生改变,而对于孔隙扁率则随颗粒形状、孔隙度等的变化有较大变化。针对这些情况,提出一种新的改进的Xu-White横波预测方法,并可取得较好的效果。     

油井动态与地震关系研究的新进展

对油井动态与地震关系进行了系统、深入研究,取得了新的进展,给出了油井动态多种观测参数间定量的相互关系数学表达式,给出了由油井压(水位)的变化反演含油(水)层应力变化的定量计算方法与程序,给出了多维的时、空、强大区域应力场的演化图像,给出了较科学的油井动态数据处理方法,对动态异常演化的时空分布特征与观测点所处的构造位置进行综合研究。     

东海八角亭海洋深井台地震监测

上海市地震局设计、建设的中国第1个真正意义上的海洋深井地震观测台位于东海石油平台上,井深780 m,安装2套JDF-1型地震计进行观测。通过对陆域地震台站记录的大地震进行分析比较、方位校准,采用单台地震分析方法,确定2009年5月—2011年6月记录到的136个地震参数,总结海域地震波形特征。结果表明,该海域地震活动性特征与当地地质构造一致。     

Advances in research on earthquake fluids hydrogeology in China: a review

Monitoring of subsurface fluid (underground fluid) is an important part of efforts for earthquake prediction in China. The nationwide network, which monitors groundwater level, water temperature, and radon and mercury in groundwater, has been constructed in the last decades. Large amounts of abnormal fluid changes before and after major earthquakes have been recorded, providing precious data for research in earthquake sciences. Many studies have been done in earthquake fluid hydrogeology in order to probe the nature of the earthquake. Much progress in earthquake fluid hydrogeology has been made in the last decades. The paper provides a review of the advances in research on earthquake fluid hydrogeology over the last 40 years in China. It deals with the following five aspects: (1) an introduction to the development history of monitoring networks construction; (2) cases of different subsurface fluid changes recorded before some major earthquakes which occurred in the last decades; (3) characteristics of subsurface fluid changes following major earthquakes; (4) mechanism of subsurface fluid changes before and following earthquakes; (5) application of earthquake fluids in the hydrogeology field.