Weak Gel Flooding Research and Effect Assessment of Horizontal Injection-Production Well Groups in Light Level of Oilfields

Weak gel flooding has been tested and achieved good results in Bohai heavy oilfields. Based on the mechanism analysis and numerical simulation study, weak gel flooding technology is believed to be effect of increasing oil and decreasing water in light oilfields. BZ S oilfield is a low-viscosity oilfield based on horizontal wells development. Due to different production online time and production rate of the well groups of injection and production horizontal wells, it caused advantageous channels formed between injection and production wells in some groups, which reduce storage rate of injection water and affect the development effect. In order to suppress the injected water onrush along the high permeability layer and improve water-oil mobility ratio and sweep efficiency, we have selected two groups for the weak gel flooding test. After flooding test, we evaluate and analyze the recovery and injection characteristics. It shows the test did not achieve the expected result. Therefore, we sum up reasons for the defeat. First, for horizontal injection wells, weak gel plugged well section of relatively pool physical property around water injection wells, increase of wellhead pressure for injection wells make it difficult to meet the requirements of injection allocation. Second, weak gel is hard to work for the pattern of spacing greater than 400m. For these two reasons, weak gel is not displaced and injected to the deep reservoir, and superior channel is still existed, not present precipitation increased the effect of oil wells. Through the evaluation and failure analysis of this displacement test, we proposed technical requirements for weak gel flooding on the horizontal group of injection and production wells. It provided practical experience and references for the other oilfields EOR tertiary oil recovery programs

Screening for postpartum hypomania among Chinese women after childbirth

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.This study examines the prevalence and risk factors for postpartum hypomania in women after childbirth as well as examining the potential influence of personality traits in relation to experiencing symptoms of postpartum hypomania A total of 1022 women no later than 1 month post-birth were recruited in Suzhou, China, between March 2017 and December 2018. Hypomanic symptoms were assessed with the Hypomania Checklist-32 (HCL-32), and a total score of 14 or higher was defined as having hypomanic symptoms. We found 43.6% of the women in our sample had hypomanic symptoms. The results of multiple logistic regression showed that rural residence [p = 0.01, odds ratio (OR) = 0.7, 95% confidence interval (CI) = 0.5-0.9], education background (p = 0.005, OR = 0.6, 95% CI = 0.5-0.9), marriage satisfaction (p = 0.048, OR = 0.9, 95% CI =0.8-1.0), Pittsburgh Sleep Quality Index (PSQI) (p = 0.001, OR = 0.9, 95% CI = 0.9-1.0), Eysenck Personality Questionnaire-Extraversion (p < 0.001, OR = 1.2, 95% CI = 1.1-1.2), Eysenck Personality Questionnaire-Lie (p = 0.01, OR = 0.9, 95% CI = 0.9-1.0), and General Anxiety Disorder-7 (p = 0.02, OR = 1.1, 95% CI = 1.0-1.1) were independently associated with exhibiting hypomanic symptoms. The current study provided insights into hypomanic symptoms in Chinese postpartum women. We also found that extraversion and lie personality were significantly associated with an increased risk of hypomanic symptoms in postpartum women. It is urgent to arrange screening for women at risk of developing postpartum hypomania as soon as possible after giving birth and at regular intervals in the first 6 months to prevent the women developing psychological disorders such as depression and bipolar disorder later on

Relationship between trait neuroticism and suicidal ideation among postpartum women in China:Testing a mediation model

BACKGROUND: Suicidal ideation is a common phenomenon among postpartum women around the world. However, evidence of the relationship between neuroticism and suicidal ideation among postpartum women is still lacking. METHODS: From March 2017 to December 2018, a total of 1027 postpartum women (assessed no later than one month post-birth) were recruited to complete questionnaires assessing neuroticism, depression, anxiety and suicidal ideation. RESULTS: Anxiety and depression fully mediated the association between neuroticism and suicidal ideation (Total indirect effects = 0.11, 95%CI: 0.07, 0.15). The indirect effect of the pathway of EPQ (Neuroticism)-Anxiety-Suicidal ideation was more significant than other pathways (Indirect effects=0.04, 95%CI: 0.02, 0.07). CONCLUSION: Interventions for suicidal ideation in postpartum women need to target neuroticism and further research is necessary understand the mechanisms by which neuroticism affects suicidal ideation

Mental health outcomes among Chinese prenatal and postpartum women after the implementation of universal two-child policy

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Background Poor health status among both pregnant and postpartum women is commonly reported worldwide. The associations between mental health outcomes and giving birth to the second child since the implementation of China's universal two-child policy have not been identified. Methods A large-scale based mental health survey was conducted between March 2017 and December 2018 in Suzhou, China. The survey evaluated the symptoms of anxiety, hypomania, depression and poor sleep quality among both pregnant and postpartum women. Results A total of 3,113 questionnaires were collected, the prevalence of anxiety, hypomanic and depressive symptoms and poor sleep quality in our sample were 3.2% (95%CI: 2.6%-3.9%), 51.7% (95%CI: 49.9%-53.4%), 12.4% (95%CI: 11.3%-13.6%) and 37.8% (95%CI: 36.0%-39.5%), respectively. Logistic regression showed that giving birth to the second child was positively associated with women's age, and was negatively correlated with higher educational level and living in rented housing. Women with the second pregnancy or child were positively associated with anxiety symptoms in the whole sample (OR=1.75, 95%CI: 1.11-2.75) and among prenatal women (OR=2.11, 95%CI: 1.16-3.83), while it was inversely correlated with depressive symptoms among postpartum women (OR=0.63, 95%CI: 0.41-0.99). Conclusions Women giving birth a second time were more prone to have anxiety symptoms among the prenatal women and the whole sample, and less likely to have depressive symptoms among the postpartum women. Efficacious measures and interventions are essential to improve maternal mental health