盐间页岩盐离子扩散对自发渗吸驱油的影响——以潜江凹陷潜江组页岩为例

潜江凹陷盐间页岩富含石盐矿物,遇到水后迅速发生盐溶解、扩散,目前对于盐离子扩散对自发渗吸驱油的影响尚不清楚。以潜江凹陷的钙芒硝质盐间页岩、白云质盐间页岩和泥质盐间页岩样品为研究对象,开展页岩油储层逆向自发渗吸实验,采用低场核磁共振测试仪监测盐间页岩的渗吸过程中的油相变化。实验结果显示渗吸水进入盐间页岩后,将孔隙中的油以油滴的形式置换、排驱出来,具有小孔吸水、大孔排油的特征。初期小孔原油排出速率较高,大孔或微裂缝中的原油含量基本不变,但随着小孔原油排出速率的下降,新生的大孔或微裂缝中原油逐渐减少。此外,渗吸过程中,骨架结构中石盐矿物迅速溶解,产生大量的溶孔、裂缝。然而,量纲分析结果表明渗吸速率与石盐矿物含量具有负相关关系,石盐矿物含量越高,渗吸速率越低。石盐矿物的溶解引起颗粒崩落,堵塞基质孔隙,对储层产生了伤害作用,反而不利于孔隙中原油向新生溶孔、裂缝中迁移。研究了盐间页岩油储层中的盐的溶解、扩散机制及其对油动态迁移特征的影响,对盐间页岩的压裂液返排制度的建立和提高页岩油产出具有重要意义

致密油储层毛细管力自发渗吸模型分析

部分致密油井压后关井一段时间,压裂液返排率普遍低于30%,但是致密油气井产量反而越高,这与压裂液毛细管力渗吸排驱原油有关。然而,致密油储层致密,物性差,渗流机理复杂,尚没有形成统一的自发渗吸模型。本文基于油水两相非活塞式渗流理论,建立了压后闷井期间压裂液在毛细管力作用下自发渗吸进入致密油储层的数学模型,采用数值差分方法进行求解,并分析了相关影响因素。结果显示渗吸体积、渗吸前缘移动距离与渗吸时间的平方根呈线性正相关关系,与经典Handy渗吸理论模型预测结果一致,说明毛细管力自发渗吸模型可靠性较高。数值计算结果表明毛细管水相扩散系数是致密储层自发渗吸速率的主控参数,毛细管水相扩散系数越高,自发渗吸速率越大。毛细管水相扩散系数随着含水饱和度先增加后减小;随着束缚水饱和度、油相和水相端点相对渗透率增加而增加;随着相渗特征指数、油水黏度比和残余油饱和度增加而减小。该研究有助于深入认识致密油储层压裂液渗吸机理,对优化返排制度、提高致密油井产量具有重要意义

草炭绿化荒漠

1993-1996年与日本草炭研究会开始“草炭绿化荒漠”的研究工作,1997-2000年开始执行中日政府间JICA合作研究,1998年9月-2001年9月开始中国科学院重大国际合作特别支持项目。该项目以中国科学院阜康荒漠生态试验站为基地,利用草炭改良荒漠,寻求绿化荒漠的新方法、新技术,改善干旱区环境为目的。研究包括草炭的基本性质、土壤-植物系统与水份关系、草炭改土效果、草炭制剂的研究制、草炭利用新技术、草炭的土壤中分解速率和利用年限、草炭绿化荒漠机理等。研制的“草炭土壤调理剂”获发明专利,该制剂可为作物提供全方位的水份和养份供应,为有机肥工业化提供了良好前景;研究方法上采用了盆栽、小区和同位素..

Workshop on Contemporary Chinese History (中国当代史研究工作坊)

journal articl

Aripiprazole versus other atypical antipsychotics for schizophrenia

BACKGROUND: In most western industrialised countries, second generation (atypical) antipsychotics are recommended as first line drug treatments for people with schizophrenia. In this review we specifically examine how the efficacy and tolerability of one such agent - aripiprazole - differs from that of other comparable second generation antipsychotics. OBJECTIVES: To evaluate the effects of aripiprazole compared with other atypical antipsychotics for people with schizophrenia and schizophrenia-like psychoses. SEARCH METHODS: We searched the Cochrane Schizophrenia Group Trials Register (November 2011), inspected references of all identified studies for further trials, and contacted relevant pharmaceutical companies, drug approval agencies and authors of trials for additional information. SELECTION CRITERIA: We included all randomised clinical trials (RCTs) comparing aripiprazole (oral) with oral and parenteral forms of amisulpride, clozapine, olanzapine, quetiapine, risperidone, sertindole, ziprasidone or zotepine for people with schizophrenia or schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: We extracted data independently. For dichotomous data we calculated risk ratios (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model. Where possible, we calculated illustrative comparative risks for primary outcomes. For continuous data, we calculated mean differences (MD), again based on a random-effects model. We assessed risk of bias for each included study. MAIN RESULTS: We included 12 trials involving 6389 patients. Aripiprazole was compared to olanzapine, risperidone and ziprasidone. All trials were sponsored by an interested drug manufacturer. The overall number of participants leaving studies early was 30% to 40%, limiting validity (no differences between groups).When compared with olanzapine no differences were apparent for global state (no clinically important change: n = 703, 1 RCT, RR short-term 1.00 95% CI 0.81 to 1.22; n = 317, 1 RCT, RR medium-term 1.08 95% CI 0.95 to 1.22) but mental state tended to favour olanzapine (n = 1360, 3 RCTs, MD total Positive and Negative Syndrome Scale (PANSS) 4.68 95% CI 2.21 to 7.16). There was no significant difference in extrapyramidal symptoms (n = 529, 2 RCTs, RR 0.99 95% CI 0.62 to 1.59) but fewer in the aripiprazole group had increased cholesterol levels (n = 223, 1 RCT, RR 0.32 95% CI 0.19 to 0.54) or weight gain of 7% or more of total body weight (n = 1095, 3 RCTs, RR 0.39 95% CI 0.28 to 0.54).When compared with risperidone, aripiprazole showed no advantage in terms of global state (n = 384, 2 RCTs, RR no important improvement 1.14 95% CI 0.81 to 1.60) or mental state (n = 372, 2 RCTs, MD total PANSS 1.50 95% CI -2.96 to 5.96).One study compared aripiprazole with ziprasidone (n = 247) and both the groups reported similar change in the global state (n = 247, 1 RCT, MD average change in Clinical Global Impression-Severity (CGI-S) score -0.03 95% CI -0.28 to 0.22) and mental state (n = 247, 1 RCT, MD change PANSS -3.00 95% CI -7.29 to 1.29).When compared with any one of several new generation antipsychotic drugs the aripiprazole group showed improvement in global state in energy (n = 523, 1 RCT, RR 0.69 95% CI 0.56 to 0.84), mood (n = 523, 1 RCT, RR 0.77 95% CI 0.65 to 0.92), negative symptoms (n = 523, 1 RCT, RR 0.82 95% CI 0.68 to 0.99), somnolence (n = 523, 1 RCT, RR 0.80 95% CI 0.69 to 0.93) and weight gain (n = 523, 1 RCT, RR 0.84 95% CI 0.76 to 0.94). Significantly more people given aripiprazole reported symptoms of nausea (n = 2881, 3 RCTs, RR 3.13 95% CI 2.12 to 4.61) but weight gain (7% or more of total body weight) was less common in people allocated aripiprazole (n = 330, 1 RCT, RR 0.35 95% CI 0.19 to 0.64). Aripiprazole may have value in aggression but data are limited. This will be the focus of another review. AUTHORS' CONCLUSIONS: Information on all comparisons are of limited quality, are incomplete and problematic to apply clinically. Aripiprazole is an antipsychotic drug with a variant but not absent adverse effect profile. Long-term data are sparse and there is considerable scope for another update of this review as new data emerges from the many Chinese studies as well as from ongoing larger, independent pragmatic trials