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The gas lift in the offshore M field will be performed with high CO2‐content associated gas, but the change of wellbore temperature and pressure during the injection process will lead to the change of phase and physical parameters of associated gas, which has a great impact on the design of gas lift. To ensure the smooth implementation of gas lift in the offshore M field, this paper conducts a study on the physical parameters of associated gas considering the change of CO2 phase state. We obtained the density, viscosity, compression factor, constant pressure specific heat capacity, thermal conductivity, and Joule Thomson coefficient at each temperature and pressure by Hysys calculation, and regression analysis to obtain the regression model of the physical parameters; finally, the regression model was compared with the flash experiment and Hysys calculation results. The results show that the CO2 phase change has a large influence on the physical parameters; R2 > 0.8, which indicates that the regression model has sufficient reliability; the results of the comparison show that the empirical formulas of all physical properties have sufficient accuracy and superiority except Joule–Thomson coefficients. In addition, the empirical formula of the Joule–Thomson coefficient also has good accuracy and superiority at the pressure not exceeding 22 MPa. The study of phase changes and physical parameters of associated gas with high CO2 content provides a basis for subsequent gas lift design in the offshore M field and multiphase flow calculations in the wellbore during the gas lift. Although this study is only applicable to this sample, it also provides a feasible research method for other samples. [ABSTRACT FROM AUTHOR]

Carbon dioxide capture and storage is the primary way to reduce greenhouse gas emissions on a large scale. Carbon dioxide storage is the critical link of this technology, and the way in which to achieve long-term storage is a problem to be considered. The elastic and anti-corrosion cement slurry is the key for the successful storage of carbon dioxide. In order to develop the cement slurry for carbon dioxide storage, the influence of resin with both elastic and anti-corrosion properties on the performance of a cement slurry was investigated. The dispersant, retarder, and filtrate reducer suitable for the cement slurry were studied, and the performance of the designed cement slurry for carbon dioxide storage was evaluated. The experimental results show that the resin can reduce water loss and improve the elasticity and corrosion resistance of cement paste. The elastic modulus and corrosion depth of the resin cement slurry were significantly lower than those of the non-resin cement slurry. By studying the dispersant and retarder, the performances of the cement slurry for carbon dioxide storage was found to be able to meet the requirements of the cementing operation. The water loss of the designed cement slurry was low, the thickening time was more than three hours, and the rheological property was excellent. The elastic modulus and corrosion depth of the designed cement slurry was very low. The cement paste had a strong resistance to damage and corrosion. The structure after corrosion was denser than the conventional cement slurry, and the characteristic peak of corrosion products was weaker. The designed elastic and anti-corrosion cement slurry was well suitable for the cementing operation of carbon dioxide storage wells. [ABSTRACT FROM AUTHOR]

Accurate prediction of extension limit of extended-reach well is of great significance for safe drilling. Hydraulic extension limit is an important part of the extended reach wells design. In this paper, the borehole size, the inner and outer diameter of the drill string are first normalized; Then, based on the definition of hydraulic extension limit, the minimum pressure loss gradient and the maximum hydraulic limit of the drilling section are established by using the inner and outer pressure loss of the drill string. A well X in Bohai Oilfield is taken as a case study to calculate the hydraulic limit before and after optimization of the drill string size under different pump pressures and mudflow rate. Finally, the hydraulic extension limit distance of X well with different optimized sizes are calculated and compared with the corresponding limit computed with API drill string size dimension under the same range of pump pressure and mudflow rate.The results showed that the optimized drill string size can increase the hydraulic limit of the designed well. When the pump pressure is 22 MPa and the mud flow rate is 40 L/s, the optimized horizontal section increased by 50.61% while the hydraulic limit of the well enhanced by 20.30%. For a pump pressure ranging from 12 to 26 MPa and a mudflow rate between 30 and 65 L/s the growth rate of hydraulic extension limit after drilling string optimization ranged between 18.47 and 22.69%. Equally, the pressure loss of the upper section and the pressure loss gradient of the drilling section should be considered in the whole drilling process, and the optimal drill string of different well sections should be selected according to the hydraulic energy distribution. Under the same conditions, the optimal drill string can maximize the hydraulic extension limit of the well. On the basis of case analysis, the optimum size of drill collar and drill pipe for hydraulic extension is recommended for drilling different hole sizes in Bohai Sea. The research results can provide theoretical guidance for Bottom Hole Assembly (BHA) design, drilling assembly optimization, extension limit enhancement, and safe drilling in extended reach wells drilling process. [ABSTRACT FROM AUTHOR]

The objectives of this study were to analyze the (1) effects of donor age and multiparity on development of in vitro fertilization (IVF) embryos after ovum pickup (OPU), (2) effects of repeated and consecutive OPU-IVF procedures on embryo development, and (3) embryo production from OPU-IVF in donors with differing embryo yields after multiple ovulation and embryo transfer technology (MOET) in Japanese Black cattle (Wagyu). Donors were pre-treated with low-dosage follicle-stimulating hormone (FSH; 200 IU total), and oocytes were collected via OPU and fertilized by IVF to generate blastocysts. The number of oocytes collected per OPU session per donor was lower in heifers (2–4 years old, 5.3 oocytes) than in primiparous and pluriparous cows (2–10 years old, 13.6–19.1 oocytes; P < 0.05). Rates of blastocyst development for oocytes from heifers (33.1%) were lower than for those from cows (2–10 years old, 44.1–54.3%; P < 0.05), and average blastocyst yield/OPU/animal was lower in heifers (3.7) than in 5–6 years old cows (10.1; P < 0.05). Donors undergoing five consecutive OPU-IVF sessions after low-dosage FSH showed similar oocyte retrieval (12.2–15.1 oocytes per OPU/animal), blastocyst development rates (35.6–45.0%), and embryo yield/OPU/animal (4.8–5.8; P > 0.05) across sessions. Additionally, embryo yield from OPU-IVF was significantly improved in animals with previous low embryo yield from MOET (5.9 vs. 2.6, respectively, P < 0.05). These results indicate that Wagyu cows with previous births can be more productive as OPU-IVF donors than heifers, and oocytes from donors undergoing to five consecutive OPU-IVF cycles are competent for embryo development without loss of embryo yield/OPU/animal. Moreover, OPU-IVF can be used for embryo production and breeding from all elite Japanese Black cattle, regardless of previous low embryo yield in routine MOET. • Wagyu heifers (2–4 years old) had lower blastocyst rates and embryo yields via OPU-IVF than cows (2–10 years old). • After 5 consecutive OPU sessions , number of oocytes collected per OPU per animal, and blastocyst rates were not different. • Low-embryo-yield donors in a MOET program can be allocated to OPU-IVF to produce more embryos. [ABSTRACT FROM AUTHOR]

Horizontal well gravel packing is the most commonly used sand control technology in offshore oil and gas fields. For extreme conditions such as deepwater, low fracture pressure formations, and long horizontal well bore length, targeted and cost-effective measures are required. According to the friction models in different stages of gravel packing process of horizontal well, the corresponding friction is calculated and compared. According to the calculation, during the entire packing process, the washpipe/screen annular friction is the largest in β wave packing stage, which reflects that higher packing pressure is required in this stage, and the formation fracture pressure is easily broken at this stage. According to the equilibrium flow velocity, the calculation method and flow chart of α -wave sand bed height were put forward. The criterion and calculation method of packing length were designed. The influencing factors of viscosity, density and leakage rate of carrier fluid on α-wave packing length were discussed. The quantitative analysis was carried out. The design and calculation method of α-β wave packing length considering the successful completion of α wave packing and the successful completion of β wave reverse packing was put forward. The corresponding software was compiled to discuss and calculate the quantitative analysis of the factors affecting the α-β wave packing length, such as the density of carrier fluid, gravel density and washpipe/screen ratio. For specific conditions, certain criteria and methods can be used to design and optimize horizontal well gravel packing length. [ABSTRACT FROM AUTHOR]

Interactions between 1-butyl-3-methylimidazolium tetrafluoroborate (IL), an ionic liquid, and Na-montmorillonite (Na-MMT) were studied under different kinetic conditions to investigate the adsorption behavior of IL by Na-MMT. The adsorption of IL by Na-MMT was rapid, with a fast rate, reaching a capacity of 0.43 mmol/g, lower than Na-MMT's cation exchange capacity (CEC) of 0.90 mmol/g. Meanwhile, the highest adsorption rate occurred at the IL concentration of 1000 mg/L. The exchangeable cation of Na-MMT could not be completely substituted by the cation group of IL regardless of the IL concentration. Stoichiometric desorption experiments confirmed that the cation exchange was the dominating adsorption mechanism for the IL adsorption by Na-MMT. The pH value of the solution between 2 and 11 had a negligible effect on the adsorption amount of IL by Na-MMT. The cation group of IL interacted into the interlayer of Na-MMT successfully, resulting in the change in the wettability of Na-MMT. A bilayer formation of the cationic group should occur in the interlayer of the modified Na-MMT and the configuration of IL was dependent on the adsorption amount of IL. Furthermore, the thermal stability of the modified Na-MMT was also dependent on the adsorption amount of IL. [ABSTRACT FROM AUTHOR]

Aluminum butylmethylphosphinate AiBMP as a flame retardant and phenolphthalein as a synergistic agent were applied in a thermoplastic polyester elastomer (TPEE)) in the current study. The thermal properties, flame retardancy, crystallization and mechanical properties of TPEE/AiMBP with or without phenolphthalein were investigated using various characterizations, including the limiting oxygen index (LOI), vertical burning test (UL 94), thermogravimetric analysis TG, differential scanning calorimetry, microcombustion calorimeter (MCC), scanning electron microscopy (SEM), and mechanical tests. The results revealed that AiBMP alone is an efficient flame retardant of TPEE. Adding 15 wt.% AiBMP increases the LOI value of TPEE from 20% to 36%. The formula TPEE-15 AiBMP passed the UL 94 V-0 rating with no dripping occurring. The MCC test shows that AiBMP depresses the heat release of TPEE. In comparison with pure TPEE, the heat release rate at peak temperature and the heat release capacity of TPEE-15AiBMP are reduced by 46.1% and 55.5%, respectively. With the phenolphthalein added, the formula TPEE/13AiBMP/2Ph shows a higher char yield at high temperatures (>600 °C), and the char layer is stronger and more condensed than TPEE-15AiBMP.The tensile strength and elongation at break values of TPEE-13AiBMP-2Ph are increased by 29.63% and 4.8% in comparison with TPEE-15AiBMP. The SEM morphology of the fracture surface of the sample shows that phenolphthalein acts as a plasticizer to improve the dispersion of AiBMP within the matrix. The good char charming ability of phenolphthalein itself and improved dispersion of AiBMP make the TPEE composites achieve both satisfying flame retardancy and high mechanical properties. [ABSTRACT FROM AUTHOR]

Japanese Black (Wagyu) cattle donors were primed with different protocols and sources of follicle-stimulating hormone (FSH) for successive ovum pickup (OPU) and embryo development after in vitro fertilization (IVF). Following OPU, retrieved cumulus oocyte complexes (COCs) were subjected to IVF, and resulting blastocysts were transferred into recipients to evaluate implantation capability. Experiment 1: The best blastocyst development (45.3 %) and embryo yields (5.0/donor/OPU) were found with oocytes retrieved from donors treated with FSH (STIMUFOL®, Belgium) at a dosage of 150 IU per donor, compared to two others commercial FSH sources. Experiment 2: There were no differences in embryo development or yield with STIMUFOL FSH (total FSH 150 IU/donor) at a priming duration of either 60-h (Regime 1, six FSH injections) or 36-h (Regime 2, four FSH injections). Experiment 3: Compacted COCs required 22–26-h maturation in vitro (IVM) before IVF for optimal blastocyst development (36.1–41.1 %); however, short (18-h) and prolonged (30-h) IVM duration resulted in lower embryonic development. In contrast, expanded COCs resulted in inferior blastocyst development compared to compacted COCs. Immunofluorescence microscopy revealed that the ratio of 89.8 % cumulus compacted COCs were at the germinal vesicle (pachytene) phase while 98.9 % cumulus expanded COCs went through spontaneous meiosis from meiotic metaphase I, anaphase I, telophase I to metaphase II upon OPU retrieval (P <0.05). Pregnancy rates were not different among three FSH sources or different FSH treatments as long as embryos reached the blastocyst stage. Our study found that different sources of FSH used for Wagyu donor priming prior to OPU resulted in differential embryo development potentials, but those embryos that reached out to blastocysts had a competent implantation ability. • Different FSH sources for priming Wagyu prior to OPU had different effects on embryo developmental potential of oocytes. • Oocytes derived from FSH-primed Wagyu cattle required a maturation duration of 22–26-h in vitro after OPU. • An optimal OPU collection procedure for Wagyu cattle oocytes. [ABSTRACT FROM AUTHOR]