本文记述了2011年采自山东蒙阴盆地常路组二段的介形类化石共计6属10种4未定种,可建立一个Me-tacypris-Paracandona-Cyclocypris-Candona-Candoniella组合.根据介形类化石与国内已知化石组合对比研究,常路组二段的时代大致为古新世—早始新世.

The creating mud cake with ultra-low filtration with drilling fluid requires the match between the pore throat size and the temporary shielding/plugging agents(TPA) particle size.A new scientific and reasonable TPA optimizing method is developed."1/3 bridging rule" and "temporarily plugging/shielding technology" mainly based on mean formation pore size works effectively for homogenous reservoir,while is difficult to seal large size pore throats in heterogeneous reservoir.Based on "the Maximum Packing Efficiency Principle","Ideal Packing Theory" and "the D90 rule",a new graphical method to optimize plugging particle size distribution was proposed,and the associated software was developed which can quickly and accurately select and recombine TPA with different particle size in a given proportion based on formation correlative parameters,such as pore throat size data.Field tests shown that drilling fluids and well completion fluids composed of optimized TPA can create fine mud cake effectively,seal pore throats with different size in heterogeneous formation.Consequently it can prevent the solid particles and filtrate of invasive fluids from entering formation.Compared with conventional temporary bridging method,this new method has smaller invasion radius(<2cm),and higher return permeability(>83%),a lower breakthrough pressure gradient(1.05MPa/m),and better reservoir protection.

本文采用前人实测不同温度不同压力下钻井液的密度数据,首次将社会科学统计软件SPSS应用到高温高压条件下钻井液密度线性回归模型中,介绍在石油工程中的应用及实现方法,确定了其有关参数和理论数据.回归拟合结果表明,将SPSS用于高温高压条件下钻井液密度模型中是合理的.并利用SPSS对影响高温高压下水基钻井液密度变化的因素进行了分析,得出钻井液密度与压力和温度之间的相关系数分别为-0.322和-0.960,相关系数检验的概率p值分别为0.045和0.

Low permeability reservoirs have characteristics such as high argillaceous cement content,high water saturation,high capillary pressure,highly water sensitive,small pore throats,poor permeability,complex structures,highly inhomogeneous,and high resistance to flow,and often are accompanied by naturally fractures.Researches had proved that water block was the most important cause for permeability impairment,with impairment percent of 70%-90%.This paper analyzed from different aspects the sources and the influential factors of water block.An amphoteric polymer sulfonate drilling fluid was developed with multiple functions,minimal damage to reservoir permeability,and ultra-low filter loss.This drilling fluid is beneficial to the development of low-permeability reservoirs.

In the paper,the statistical package for social science(SPSS) is used in the linear regression model of HTHP drilling fluid density for the first time based on the density data measured under different temperatures and pressure. The paper introduces the application and implementation method in petroleum engineering and determination of related parameters and theoretical data.The regression fit result indicates that application of SPSS in HTHP drilling fluid density model is reasonable.The factors which influence HTHP water-base fluid density are analyzed with SPSS.It is obtained that the correlation coefficients between drilling fluid density and pressure and temperature are -0.322 and -0.960 for each.The probability p values of correlation coefficient checkout are 0.045 and 0.

For the purpose of reducing drilling fluid expense and solving the problems occurred in Dagang Oilfield,including formation collapse,pipe-sticking,the positive-charged polyglycol/potassium chloride drilling fluids were optimized by orthogonal test designing software-SPSS13.0 based on the analysis of the formation clay and evaluation of the treating agent.Laboratory studies show that this fluid system has better inhibitive capacity,rheology,filtration,anti-pollution and lubricity.This paper also investigates the working mechanism of the mud and shows that positive-charged polyglycol and potassium chloride have synergistic effects,which helps hole cleaning and wellbore stability.