In recent years, a unique electrical submersible reciprocating pumping system (ESRP) was developed and has been applied in Daqing Oilfields. The main structure of ESRP is similar with ESP, consisting of an electrical submersible motor, pump, tubing and cable. The key equipments of ESRP are the reciprocating motor and the pump. The motor is a novel permanent magnetic line motor consisting of stator and mover. The pump is a special reciprocating pump. In operation, the mover slips in the stator from one end to the other periodically controlled by surface equipment, applying the power to the plunger of the reciprocating pump. Because of its small outerdiameter, the whole system could be run into the horizontal wellbore conveniently.
This unique lifting system was designed mainly for the production of satellite oilfields in Daqing Oilfield. Unlike the properties of the main blocks of Daqing Oilfield with thick pay zones, high permeability and shallow imbedded reservoir, these satellite oilfields distributed discontinuously, the layers are thin and imbedded deeply with poor permeability. The producers’ averaged production is below 35 bpd. Beam pumping system showed poor benefit due to the high investment and operating cost. PCPs and Bailing lifting systems were applied later in a larger scale. But the management was relatively complicated and still limited in horizontal wells. As the result, ESRP showed great advantages both in technical and economic respects in the production.
Till the end of 2010, ESRP has been applied in more than 30 wells in Daqing Oilfield. The longest running life has reached above 400 days. It showed remarkable advantages in the production of low displacement and deep reservoir, especially for horizontal wells.
With the improvement of displacement and other specifications, this unique lifting system design has great potential in the development of unconventional reservoir as well as mature oilfields.
This study analyzed the partial effect of carbon dioxide hydrate in reaction kettle experiments. The particle and bubble characteristics of the crystal nucleus during carbon dioxide hydrate decomposition were observed under the microscope. The results showed that in the temperature range of 0.5°C-3.5°C, the pressure range of 3 MPa-5.5 MPa, phase characteristics in the reaction kettle changed in a complex fashion during carbon dioxide hydrate formation. During hydrate decomposition, numerous carbon dioxide bubbles were produced, mainly by precipitation at high temperatures or in the hydrate cage structure. The hydrate crystal nucleus initially exhibited fluidity in the reaction. However, as the reaction progressed, the hydrate crystal nucleus migrated upward under the influence of gravity and carbon dioxide diffused into the aqueous phase. Next, the hydrate was formed and accumulated, finally forming a solid carbon dioxide hydrate layer.
Background
Tuberculosis (TB) is still the single pathogen infectious disease with the largest number of deaths worldwide. The relationship that intestinal microbiota disorder and de novo fatty acid synthesis metabolism have with disease progression in multi-drug resistant TB (MDR-TB) has not yet been fully studied.
Objective
To investigate the effects of long periods of MDR-TB, pre-extensively drug-resistant TB (pre-XDR-TB), or rifampicin-resistant TB (RR-TB) on gut microbiome dysbiosis and advanced disease.
Methods
The sample was chosen between March 2019 and September 2019 in Wenzhou Central Hospital and comprised 11 patients with pre-XDR-TB, 23 patients with RR-TB, and 28 patients with MDR-TB. Healthy individuals were chosen as the control group (CK group). An overnight fast blood sample was drawn via venipuncture into tubes without anticoagulant. For analysis, 300 mg of faeces from patients from the same group was mixed and analysed using DNA extraction, NGS sequencing, and bioinformatics. A QIAamp Fecal DNA Mini Kit was used to isolate the DNA. The extracted DNA was stored at −20°C.
Results
Advanced TB was concurrent with an elevated level of the proportions of acetyl-CoA carboxylase (ACC1) to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and fatty acid synthase (FASN) to GAPDH in de novo fatty acids synthesis, and
Eubacterium, Faecalibacterium, Roseburia
, and
Ruminococcus
were increased significantly in RR-TB patients compared to healthy individuals, whereas their abundance in the pre-XDR-TB and MDR-TB groups showed little change in comparison with the control group.
Proteobacteria
levels were greatly increased in the RR-TB and MDR-TB patient groups but not in the patients with pre-XDR-TB or the healthy subjects. The pre-XDR-TB group exhibited alterations of the intestinal microbiome: coliform flora showed the highest abundance of
Verrucomicrobiales, Enterobacteriales, Bifidobacteriales
and
Lactobacillales
. De novo fatty acids synthesis was enhanced in patients and was associated with the gut microbiome dysbiosis induced by the antimicrobials, with
Bacteroidetes, Bacteroidales
, and
Bacteroidaceae
displaying the most important correlations on a phylum, order, and family level, respectively.
Conclusion
The progression to advanced TB was observed to be a result of the interaction between multiple interrelated pathways, with gut–lung crosstalk potentially playing a role in patients with drug-resistant TB.
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