Fluid Formation Research Articles

Experimental Study on a Liquid-Solid Phase-Change Autogenous Proppant Fracturing Fluid System.

In this paper, a liquid-solid phase-change autogenous proppant fracturing fluid system (LSPCAP) was proposed to solve the problems that was caused by "sand-carrying" in conventional fracturing technology in oil and gas fields. The characteristic of the new fluid system is that no solid particles will be injected in the whole process of fracturing construction except liquids. The fluid itself will transform into solid particles under the formation temperature to resist the closure stress in the fractures. There are two kinds of liquids that make up the new fracturing fluid system. One of the liquids is called phase-change liquid (PCL) which occurs in the liquid-solid phase change under the formation temperature to form solid particles. Another is called nonphase-change liquid (NPCL) which controls the dispersity and size of PCL in the two-phase fluid system. Based on the molecular interaction theory and organic chemistry, bisphenol-A epoxy resin was selected as the building unit of the PCL, and the NPCL consisted of deionized water + nonionic surfactant. The test results indicated that the new fracturing fluid shows the properties of non-Newtonian fluid and has no wall-building property. The new fluid system has good compatibility with the formation fluid, conventional fracturing fluid, and hydrochloric acid. Through the filtration test, the filtration coefficients of PCL, NPCL, and mixture are found to be 1.56 × 10-4 m/s1/2, 2.66 × 10-4 m/s1/2, and 1.7 × 10-4 m/s1/2, respectively, and the damage rate of mixture and NPCL is 18 and 17.7%. The friction test results show that the resistance reduction rate reaches 69% when the volume ratio of PCL and NPCL is 1:10. The shear rate and time only affect the size of the autogenous solid particles, and the sorting coefficient (S) of the particles is 1.04-1.73, indicating good sorting. Crushing resistance and conductivity test results show that the crush rate of autogenous solid particles is 3.56-8.42%. The conductivity of the autogenous solid particles is better than those of quartz sand and ceramsite under a pressure of 10-30 MPa.

4D Seismic Least Square Migration in Carbonates: A Case of Successful Matching

4D seismic surveys are now routinely used to monitor hydrocarbon reservoirs. Because seismic reflections are sensitive to formation stress and fluid content, repeated seismic surveys are able to detect pressure changes and fluid exchanges that occur during field production. These measurements can help to optimise recovery strategy and identify areas where hydrocarbons have been bypassed. In practice, the seismic signal associated with such changes may be negligible, especially in heterogeneous carbonate reservoirs. However, by applying a 4D seismic co-processing workflow, we were able to detect and quantify a 4D signal even with suboptimal repeated acquisition geometry. Seismic inversion helped to overcome noise, multiple contamination, and differences in dynamic amplitude range between baseline and monitor seismic surveys. Matching the 4D seismic signal to changes in reservoir production characteristics aided in the investigation of the mechanism underlying the observed 4D signal. Detectability of 4D signals was found to be primarily related to changes in reservoir pressure and fluid saturation, which increased from 2010 to 2020 the time-lapse between the base and monitor survey.

Abstract OT3-20-04: SerMa – Seroma formations of the Mammary gland in breast cancer patients after mastectomy and implant-based reconstruction (EUBREAST 5)

Abstract Background Postoperative seroma formations are one of the most common and serious complications after implant-based breast reconstruction and can lead to implant and thus breast loss. The cause hasn`t yet been clarified. Hypothesis generating and thus as a basis for this multicenter study is the suspicion of a connection between immunological-inflammatory processes that promote the development of a seroma. First promising results of the pilot phase (SerMa pilot) have been published and gave the first impulse for this study. Trial design The SerMa (EUBREAST 5) study is a prospective, multicenter, interventional, international study including patients with primary breast cancer and a skin-/nipple-sparing mastectomy combined with an implant-based reconstruction method. Control groups were chosen to work out common group-specific differences. Intra- or directly preoperatively collected blood as well as intraoperatively collected local smear using swabs are preserved specimens. Follow-up includes visits after 2 and 6 weeks as well as after 6 months. In case of a seroma formation fluid aspirations are preserved for laboratory analyses. Eligibility criteria: The study population contains patients with primary diagnosis of breast cancer scheduled for skin-/nipple-sparing mastectomy and implant-based breast reconstruction. The three control groups are: one with simple mastectomy without breast reconstruction as well as healthy persons with implant insert but without breast cancer after bilateral risk reducing mastectomy or last in case of purely cosmetic implant placement. Specific aims: The main objective of the study is to identify a patient subgroup with an increased risk of seroma development for future precision elucidation regarding the prevention of postoperative complications such as implant and thus breast loss. FACS-/Bioplex and microbiome analyses will be applied for the detection of certain immune markers, microbiobes and microbiome diversity using preoperative blood samples, intraoperative local smear collection and in case of later seroma formations also postoperative seroma aspirations. Secondary endpoints include the comparison of these factors and elaborate differences between study and control groups. Furthermore clinico-pathological factors as well as different surgical methods are compared. Statistical methods: A statistical plan for this analysis was specifically developed (Power analyses with Wilcoxon-Mann-Whitney test) and leads to a number of 300 participants per group. Target accrual: Planned start: Q1/2023 Contact: EUBREAST e.V. Citation Format: Nina Ditsch, Nicole Pochert, Udo Jeschke, Mariella Schneider, Melitta Koepke, Maggie Banys-Paluchowski, Claudia Traidl-Hoffmann, Christian Dannecker, Thorsten Kühn. SerMa – Seroma formations of the Mammary gland in breast cancer patients after mastectomy and implant-based reconstruction (EUBREAST 5) [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT3-20-04.

Magnetorheological and Viscoelastic Behaviors in an Fe-Based Amorphous Magnetic Fluid

A novel magnetic fluid was obtained using a colloidal dispersion of amorphous magnetic Fe-Ni-B nanoparticles into water. Its magnetorheological and viscoelastic behaviors were all investigated. Results showed that the generated particles were spherical amorphous particles 12-15 nm in diameter. The saturation magnetization of Fe-based amorphous magnetic particles could reach 49.3 emu/g. The amorphous magnetic fluid exhibited shear shinning behavior under magnetic fields and showed strong magnetic responsiveness. The yield stress increased with the rising magnetic field strength. A crossover phenomenon was observed from the modulus strain curves due to the phase transition under applied magnetic fields. The storage modulus G' was higher than the loss modulus G″ at low strains, while G' was lower than G″ at high strains. The crossover points shifted to higher strains with increasing magnetic field. Furthermore, G' decreased and fell off in a power law relationship when the strain exceeded a critical value. However, G″ showed a distinct maximum at a critical strain, and then decreased in a power law fashion. The magnetorheological and viscoelastic behaviors were found to be related to the structural formation and destruction in the magnetic fluids, which is a joint effect of magnetic fields and shear flows.

Dynamics of Morphological Changes in Oral Fluid in the Prevention of Fissure Caries in Children

The purpose of the study was to investigate the morphological properties of oral fluid in dynamics in the application of the developed set of measures for the prevention of fissure caries of the first permanent molars in children. Materials and methods. 62 children aged 6 years with fissure caries of the first permanent molars (main group) and 31 children without signs of carious lesions (control group) were examined. The study of the crystal formation of oral fluid was carried out according to the method of Leus P. A. (1977). The mineralizing potential of oral fluid was expressed as an average score depending on the types of crystals detected. Results and discussion. The analysis of the results of the study showed that 6 months after the start of preventive measures in the oral fluid of the children of the main group, a slight increase in type I crystals was noted in comparison with the initial data (40.18 ± 4.65% of cases, p>0.5), at the same time, the number of children, in whom type III crystals were observed, decreased in the main group (16.45 ± 2.32%, p>0.5), and increased in the control group (19.32 ± 2.47% of cases, p>0.5) in comparison with the initial data. After two years of observation, in the children of the main group, type I crystals were most often detected in the oral fluid (48.41 ± 4.23% of cases), in the children of the control group, on the contrary, the number of children with this type of crystals decreased and was almost one and a half times less than among children of the main group (p<0.05). On the other hand, the number of children in the control group, in whom type III crystals were detected, was two times higher than among children in the main group (22.34 ± 2.87% and 11.51 ± 2.56% of cases, respectively, p<0.05). Conclusion. It was established that in children who received a complex of preventive measures, 6 months after the implementation of preventive measures, the mineralizing potential of oral fluid was, on average, 2.73 ± 0.07 points, which is slightly higher compared to the fissure detected at the beginning of caries prevention (2.57 ± 0.12 points respectively, p>0.05). In the children of the control group, the mineralizing potential of oral fluid changed less noticeably (from 2.64 ± 0.11 points at the beginning of observation to 2.66 ± 0.11 points, p>0.5). After two years of observation, it was found that in the main group the mineralizing potential of oral fluid continued to increase, while in the children of the control group it decreased and reached almost the initial level (2.65 ± 0.07 points in the second year of observation and 2.64 ± 0.08 points at the beginning, p>0.05). Thus, it can be concluded that the proposed measures are quite effective

Reverse Circulation Displacement of Miscible Fluids for Primary Cementing

AbstractPrimary cementing is the well construction operation where drilling fluid is displaced from the annular space behind the casing string, and replaced by a cement slurry. The annular cement sheath is a critical barrier element that should provide zonal isolation along the well and prevent uncontrolled flow of formation fluids to the environment. We present a combined experimental and computational study of reverse circulation displacement of the annulus, corresponding to operations where cementing fluids are pumped down the annulus from the surface. We focus on iso-viscous displacements in a vertical and concentric annulus, and vary the density hierarchy among the fluids to study both stable and density-unstable displacement conditions. While the interface between the two fluids is advected according to the laminar annular velocity profile for density-stable and iso-dense displacements, considerable secondary flows and fluid mixing is observed for density-unstable cases. Increasing the imposed velocity from the top is seen to provide a certain stabilizing effect by suppressing backflow of the lighter fluid and reduce the magnitude of azimuthal fluctuations. Computational results are in qualitative agreement with the experiments, and support the categorization of the displacement flows as either inertial or diffusive, in accordance with previous work on buoyant pipe displacements.

Study on gas injection development effect of tight reservoir based on fluid occurrence state

Based on the tight oil reservoir conditions of Lucaogou Formation in Jimusar Sag, Xinjiang, this paper conducts a full-scale characterization experiment of pore structure and designs the optimization numerical simulation of the development scheme based on the geological model combination with the fluid occurrence state. A comparative study on the development methods of tight reservoirs shows that the enhanced oil recovery effect of CO2 flooding is obviously better than that of CH4 flooding and water flooding. When the production bottom hole pressure is lower than the formation fluid saturation pressure, changing the production bottom hole pressure has little impact on the productivity of CO2 flooding in tight reservoirs. The recovery factor increases with the increase of injection rate, but when the injection rate is higher than 15,000 m³/d, the increase of oil recovery and the oil change rate decrease obviously; The complex fractures near the well can help to increase the swept volume of CO2 flooding, while the complex fractures far away from the well will cause channeling, which is not conducive to production. Combined with the occurrence state of the fluid, it is obtained that in the process of CO2 displacement, when the adsorption is considered, when the adsorption components are the same, with the increase of the adsorption capacity, the recovery factor decreases; When the adsorption capacity is constant, the higher the proportion of heavy components is, the lower the recovery factor is; With the increase of adsorption capacity, the permeability decreases more. The fluid occurrence state in tight oil reservoirs is very different from that in conventional reservoirs, and the adsorption phase accounts for a larger proportion, which seriously affects the flow capacity of the fluid during the development process. However, conventional numerical simulation rarely considers the influence of fluid occurrence state.

Fluid evolution and metallogenic mechanism of the Xianghualing skarn-type Sn deposit, South China: Evidence from petrography, fluid inclusions and trace-element composition of cassiterite

The Xianghualing Sn-polymetallic deposit is a large skarn-type Sn deposit located in the Nanling polymetallic metallogenic belt, South China. The ore bodies are controlled by NE-trending faults and mainly hosted in the contact of Middle Devonian carbonate rock and granite. The Xianghualing deposit is divided into four mineralization stages, and two stages of Sn mineralization are identified. The mineralization stages from early to late include stage I (prograde stage), stage II (retrograde stage), stage III (cassiterite-magnetite-arsenopyrite-topaz-quartz stage), stage IV (sphalerite-galena-pyrite-chalcopyrite-quartz-calcite stage). Stage II is the initial stage of Sn mineralization where only minor cassiterite precipitates, and stage III is the main Sn mineralization stage where abundant cassiterite precipitates. On this basis, fluid inclusion microthermometry and Raman spectroscopy analyses were carried out for ore and/or gangue minerals at different stages. In addition, trace element composition analysis was also conducted on cassiterite. These data can contribute to reveal the fluid properties, evolution and formation mechanism of Xianghualing deposit. Three types of fluid inclusions were identified in different mineralization stages, including halite-bearing multi-phase inclusions (Type B), liquid-rich two-phase inclusions (Type L) and vapor-rich two-phase inclusions (Type V). Garnet (stage I) contains Type B inclusions and Type V inclusions, with homogenization temperatures and salinities of 511–549 °C, 37.6–48.9 wt% NaCl equiv. and 551–559 °C, 4.0–5.1 wt% NaCl equiv., respectively. Topaz (stage II) contains Type L inclusions with homogenization temperatures of 408–445 °C and salinities of 9.5–12.4 wt% NaCl equiv. Cassiterite (stage III) contains Type L inclusions with homogenization temperatures of 368–417 °C and salinities of 8.7–11.5 wt% NaCl equiv. Quartz (stage IV) contains Type L inclusions with homogenization temperatures of 162–227 °C and salinities of 2.6–5.0 wt% NaCl equiv. The temperature and salinity of the fluid from stage I to stage II decreased significantly, recording intense meteoric water mixing. The temperature of the fluid decreased from stage II to stage III, while the salinity changed little, indicating that, except for minor meteoric water mixing, cooling of fluid is predominant. The temperature and salinity of the fluid from stage III to stage IV continued to decrease, recording the further mixing of meteoric water. From stage II to stage III, the evolution temperature of the fluid is basically consistent with the temperature indicated by trace elements (Nb, Ta, Ti) of cassiterite in the two stages. Fluid mixing may be the predominant mechanism for the minor Sn mineralization occurred in stage II. Fluid cooling may be the predominant mechanism for the abundant cassiterite precipitation in stage III, which is accompanied by redox reactions of Sn (II)-Cl complexes with As (III) and/or CO2 as potential oxidants, and acid neutralization of carbonate rocks. Combined with the cassiterite composition, it is indicated that the ore forming fluid of the Xianghualing deposit mainly derived from the highly evolved granitic magma in the region, and the genesis of cassiterite is consistent with that of typical skarn-type Sn deposits.

Exploring the role of the structural heterogeneity of fractured carbonate reservoirs in contact with dissolved CO2 based on fracture-water-rock simulation experiments

Based on the geological background of ultra-deep fractured carbonate reservoirs in the Shunbei oil and gas field, the objective of this study was to clarify the interactions between fractured carbonate reservoirs and formation fluids (brine with dissolved CO2) under deep strata, and the potential impact of these interactions on reservoirs. In this study, high-temperature and high-pressure simulation experiments and numerical simulations based on the Yijianfang Formation in the Shunbei area were designed to investigate the influence of temperature, pressure, fluid, and structural heterogeneity on fluid transport and mass transfer, calculate the ion diffusion characteristics and the trend of mineral dissolution/precipitation along the fractures, and clarify the change in the reservoir space. The results indicated that the volume of the main fracture increased after the reaction between an acidic solution and a formation sample, the permeability of the sample increased by orders of magnitude, and its porosity increased accordingly. The overall reaction during the experimental period was dominated by the dissolution of calcium carbonate, and no calcium carbonate precipitated. The structural heterogeneity and hydraulic properties of the sample make the main flow channel a main fracture. The flow and reaction processes in the flow channel promoted each other. The effects of temperature and pressure on the overall reservoir space were insignificant. Branch fractures or microfractures can weaken the main fluid flow rate and tend to result in the accumulation of solutes, the ends of which may be potential locations for mineral precipitation. Therefore, the priority exploration location for deep and ultra-deep fractured reservoirs should be the main fractures upstream of the fluid flow.

Obviating Postoperative Chyle Leaks in Vascularized Lymph Node Transfer

Objective: Lymphedema is a progressive, debilitating condition affecting up to 250 million people worldwide. Caused by the accumulation of proteinaceous interstitial fluid secondary to lymphatic destruction, extravasation of protein-rich fluid occurs when fluid formation exceeds lymphatic transport capacity, furthermore, leading to increased intralymphatic pressure, valvular incompetence, and dermal backflow, preceding eventual irreversible extremity enlargement, progressive fibrosis with lymphatic obstruction, and luminal obliteration. In western countries, damage or removal of regional lymph nodes by surgery, radiation, tumor invasion, or as a result of infection or inflammation are the most common causes of secondary lymphedema, with the greatest prevalence among those who undergo extensive axillary surgery followed by axillary radiation, noting incidences of 24-49% after mastectomy. The variability of lymphedema and increased healthcare cost in association, reins focus and elucidates the vital importance of discovering techniques to abate disease potentiation while implementing healthful strategies. Surgical techniques aim to diminish the size of the affected extremity, with resultant improvement in appearance, function, and prevention of infection; notably, growing bodies of evidence support the effectiveness of modern surgical techniques in ameliorating the long-term disability and functional impairment. Such technique of autologous vascularized lymph node transfer will be examined here. Consequently, irrespective of surgical approach, vascularized lymph node transfer affords inherent risks of postoperative chyle leaks. While previous trials have demonstrated Adherus Dural Sealant as being 99.1% effective in preventing cerebrospinal fluid (CSF) leaks through 14 days of postoperative follow-up, we will reveal Adherus Dural Sealant results within and throughout our institution, in preventing postoperative chyle leaks after vascularized lymph node transfer. Methods: In this study, we evaluate ten patients who underwent vascularized lymph node transfer between 2018 and 2021, at our single institution. Results: Within our patient population, there were a total of 13 vascularized lymph node transfers performed, with zero postoperative chyle leaks or donor site complications. Conclusion: The core plastic surgery concept of replacing “like” with “like” is no more evident than in the restoration of healthy lymph nodes to a limb in which lymphatic flow has been disrupted. In parallel to the aforementioned concept, via utilization of Adherus Dural Sealant within the supraclavicular lymph node basin and no evidence of chyle leaks in the postoperative period, we pose a novel sealant technique in lymph node harvest that has demonstrated success in minimizing complications following vascularized lymph node transfer throughout our patient series. Further research, characterization, and long-term supraclavicular lymph node basin follow-up are vital, to clarify and potentially expand upon its indications for use. Corresponding Author: Kaitlyn Stevens, DO, 6100 E. Colony Rd., Elsie, MI 48831

Sustainable Strategy for Gas Supply in China: Based on Foam Drainage Gas Recovery Technology

With the increasing demand of natural gas in China, its production is extremely important to fulfill the requirement of society. However, in reality, the natural gas production from the gas well in the gas field is often accompanied by the production of formation water. For gas well with low production, the gas flow rate in the well is too low to carry out the formation water from the bottom of the well. The water will thus accumulate in the well bore and the gas production will be greatly diminished. To solve this problem, based on the developing status of M gas field in China, foaming surfactant Z301 is synthesized and then foaming agent ZK3012 is developed through combination of Z301 with CAT after optimization experiments. After that, the compatibility tests are conducted to ensure that ZK3012 can work together well with formation fluids, and the water carrying rate tests are conducted concerning the optimum concentration of ZK3012. Finally, pilot test is conducted in 2 gas wells on site in M gas field, good results are obtained that accumulated water is discharged by foam drainage and the gas well production is increased. Studies demonstrate the main steps involved for application of this technology. In regard to the high external dependence degree of China in gas supply, operators of gas fields should give prominence to related studies of this technology to achieve sustainable development.

Vortex of viscoelastic fluid electroosmotic flow at the micro-nanochannel interface

The research on ion transport and vortex formation of viscoelastic fluids at the interface of micro-nanochannels may provide a new solution to improve the efficiency of analyte preconcentration in the ion depletion zone. The electroosmotic flow of a viscoelastic fluid in a nanochannel connecting two reservoirs was numerically investigated using the Navier-Stokes model, the Poisson-Nernst-Planck model, and the Oldroyd-B constitutive model. The results show that viscoelasticity suppresses the vortices in the ion depletion zone and breaks the symmetry of the vortices. Viscoelasticity also imparts a time dependence of vortex structure and velocity. When cKCl is 1 mM, the ratio of the average velocity at the upstream to the average velocity at the downstream for the viscoelastic fluid with the PAA concentration of 1000 ppm reaches 1.42, while it is only 0.70 for the Newtonian fluid. This study has positive significance for the development of nanochannel-based biosensing technology.

Analysis of influencing factors on wellbore instability for high-pressure gas well during testing and production

Unlike normal-pressure gas wells, wellbore instability is more likely to occur during testing for high-pressure gas wells. Gas acceleration effect exists in gas flow during high-pressure gas well testing, which was ignored in previous wellbore instability analysis. In this paper, the developments of effective circumferential stress and effective radial stress are analyzed in the near-wellbore area of high-pressure gas well, considering the influence of in-situ stress non-uniformity and acceleration effect. To analyze the effective circumferential stress and the effective radial stress more accurately, it is established that the fluid-structure coupling stress field of the finite large thick wall cylinder The flow field considers three cases, namely Darcy’s law, Darcy–Forchheimer model and Darcy-Forchheime model considering gas acceleration. The results show that in-situ stress non-uniformity has a similar influence on tensile failure and shear failure. It is observed that the location of occurring shear failure and tensile failure may not be on the wellbore wall. When the formation fluid is under abnormally high pressure, it is more likely to have a tensile failure, while when the formation fluid is under abnormally low pressure, it is more likely to have a shear failure. The Biot parameter has the same effect on tensile failure and shear failure. These results are helpful to control sand production during testing and production for high-pressure gas wells.

Assessment of resin systems as solution for well integrity challenge in carbonate reservoirs

Well integrity is defined as technical, operational, and organizational solutions specifically aimed at the reduction of the risk of formation fluids release throughout a well's life cycle. Cement integrity is one of the main aspects that comprises well integrity. Cement integrity must be ensured throughout a well's life cycle as well as after abandonment. If the cement was to lose its integrity, the consequences for the personnel, the equipment, and the environment could be severe. Cement failures might lead to leakages that can seep through the cement pathways; sealant materials are used to plug these pathways. The actual and real-time disputes are mainly dependent on the technical approaches currently available to limit the main causes of well integrity deficiency. These include cementing jobs, substantial design based on downhole conditions, material selection criticality, well construction performance, and technological resources. Additionally, in this specific context, well integrity also refers to the control of the flow inside the wellbore (between different horizons) and the flow from the well (especially in the annulus behind the casing). The worst-case scenario would be the loss of wellbore integrity, and it would be identified as the collapse of the well caused by failure of the construction material. The focal point of the research presented in this paper is the cement quality and its role in developing the most vigorous well casing possible. The focus was centered around resin additives such as microbond, latex, and crystal seal. Microbond is a white mineral cement-based liquid with exceptional performances when combined with cement. Latex is composed of rubber particles dispersed in water, usually found in white liquid form. Crystal seal is a yellow colloidal material highly regarded for sealing properties when mixed with concrete mixtures. These additives were individually incorporated into cement-based samples, in varying concentrations, for testing the changes in properties suitable for well integrity considerations. Highly specialized and sophisticated cement testing apparatuses, such as the ultrasonic cement analyzer (UCA), static gel Strength machine (SGSM), and curing chamber, have been used to perform qualitative and quantitative property gradient tests. Based on the performed experimental tests results, the optimal additive resin for a class G cement slurry is the microbond additive at a concentration of 7.5%. The results highlighted its ability to enhance the cement compressive strength by 52%. Additionally, the transit time showed a 26–42% range decrease in the travel period, indicating that the cement was stronger under increased pressure and temperature. This can clear up the permeable section of the well wherein the cement-resin slurry could efficiently close off wellbore intersecting faults and, therefore, prevent possible connections between the wellbore and water zones in the subsurface. As a result, microbond, latex, and crystal seal, respectively, show the effect of varying controlled conditions as functions of the increase in concentration, curing time, and temperature to its comparable properties such as breakload, compressive strength, and ultimate break force. This study can further support future analysis in improving the reliability of petroleum well constructions.

The indicator study role in determining path of motion of formation fluids in the development of a fractured reservoir field

The high rate of oil production with the use of water flooding, complex geological and physical conditions of the carbonate reservoir of the deposit (fractures, faults) lead to progressive watering of the extracted products.
 The field has considerable oil reserves and is at the development stage II, the average water cut is more than 60%, most of the remaining reserves pass into reserves difficult to recover category. This article focuses on determining relations between blocks and practical application of the results of indicator study method in order to determine the porosity and permeability properties of fractured carbonate formations. According to this study method, the introduction of complementary technologies to improve the existing development system was proposed.

Improved SVR based on CARS and BAS for hydrocarbon concentration detection

As one of the main means of discovering and evaluating oil and gas reservoirs, gas logging technology plays an irreplaceable role in oil and gas reservoir exploration. However, with the increasing complexity of oil and gas reservoir exploration, gas logging technology has gradually shifted from chromatographic gas logging to infrared spectral gas logging. Infrared spectroscopy logging technology can not only quickly analyze the content of hydrocarbon components in formation fluids, but also has the advantages of no pollution, high detection efficiency, and accurate analysis. However, there are many types of hydrocarbon gases in formation fluids and a wide range of concentration ranges. How to ensure that infrared spectroscopy can accurately measure the content of hydrocarbon gases is an urgent problem to be solved. To solve this problem, this paper proposes the beetle antennae search algorithm (BAS) combined with the competitive adaptive reweighted sampling (CARS) to improve the SVR for modeling. Firstly, the characteristic wavelength points of the sample set are obtained by CARS, and then the parameters of SVR are optimized by BAS, and then the corresponding high, medium and low concentration prediction models are established. The experimental results show that the accuracy and efficiency of the proposed CARS-BAS-SVR method in the quantitative analysis of hydrocarbon gas components are better than those of the traditional method. Its prediction accuracy for low-concentration hydrocarbon gases is greatly improved, and the overall average error is less than 1‰. It effectively improves the detection accuracy of infrared spectroscopy logging technology, and provides support for the further promotion of infrared spectroscopy in gas logging.

Diamonds reveal subducted slab harzburgite in the lower mantle

AbstractCharacterizing compositional heterogeneity in Earth’s lower mantle is critical to understanding its dynamics. Three low-nitrogen diamonds from Koffiefontein (South Africa), containing inclusion assemblages of ferropericlase ± orthopyroxene ± magnesite, constrain diamond formation in an Mg-rich lower-mantle environment. Ferropericlase inclusions have Mg# 82.7–88.5 and orthopyroxene inclusions (retrogressed bridgmanite) have Mg# 95.0–95.1 and mantle-like δ18O of +5.6‰ ± 0.2‰. Magnesite included in one diamond implicates carbonated fluids in diamond formation. High Mg# and low Ca, Al, and Na of the assemblage indicate a melt-depleted meta-harzburgitic environment, in contrast to more fertile compositions expected for primitive lower mantle. Extremely low Ca in orthopyroxene inclusions may reflect a combination of melt depletion and low equilibration temperatures at the time of trapping. Inclusion compositions implicate subducted oceanic slab meta-harzburgite as the host for diamond growth. Mantle-like δ18O of the orthopyroxene inclusions indicates unaltered oceanic lithosphere. Similar melt-depleted characteristics in lower-mantle inclusion assemblages worldwide support that meta-harzburgite is the dominant host of lower-mantle diamonds.

Neonatal NET-Inhibitory Factor improves survival in the cecal ligation and puncture model of polymicrobial sepsis by inhibiting neutrophil extracellular traps.

Neutrophil extracellular traps (NETs) clear pathogens but may contribute Q8 pathogenically to host inflammatory tissue damage during sepsis. Innovative therapeutic agents targeting NET formation and their potentially harmful collateral effects remain understudied. We investigated a novel therapeutic agent, neonatal NET-Inhibitory Factor (nNIF), in a mouse model of experimental sepsis - cecal ligation and puncture (CLP). We administered 2 doses of nNIF (1 mg/ kg) or its scrambled peptide control intravenously 4 and 10 hours after CLP treatment and assessed survival, peritoneal fluid and plasma NET formation using the MPO-DNA ELISA, aerobic bacterial colony forming units (CFU) using serial dilution and culture, peritoneal fluid and stool microbiomes using 16S rRNA gene sequencing, and inflammatory cytokine levels using a multiplexed cytokine array. Meropenem (25 mg/kg) treatment served as a clinically relevant treatment for infection. We observed increased 6-day survival rates in nNIF (73%) and meropenem (80%) treated mice compared to controls (0%). nNIF decreased NET formation compared to controls, while meropenem did not impact NET formation. nNIF treatment led to increased peritoneal fluid and plasma bacterial CFUs consistent with loss of NET-mediated extracellular microbial killing, while nNIF treatment alone did not alter the peritoneal fluid and stool microbiomes compared to vehicle-treated CLP mice. nNIF treatment also decreased peritoneal TNF-a inflammatory cytokine levels compared to scrambled peptide control. Furthermore, adjunctive nNIF increased survival in a model of sub-optimal meropenem treatment (90% v 40%) in CLP-treated mice. Thus, our data demonstrate that nNIF inhibits NET formation in a translationally relevant mouse model of sepsis, improves survival when given as monotherapy or as an adjuvant with antibiotics, and may play an important protective role in sepsis.

Some aspects of the diagnosis of osteopenic syndrome in workers of vibration-hazardous professions

Introduction. The adverse effects of both production factors and the labour process affect the bone mineral density, increasing the risk of developing osteopenic syndrome in workers of harmful industries, which is an urgent social and hygienic problem due to the high prevalence and severity of medical and social consequences. Objective. The study of the state of bone tissue in miners whose occupational activities are associated with the impact of vibration (general and local). Materials and methods. For the period 2015-2022, there were examined three hundred twenty mining workers, whose activities were associated with exposure to general and local vibration (group 1). The average age of the workers was 46.64±2.33 years. The comparison group (Group 2) consisted of 290 men without identified pathology of the musculoskeletal system, not employed in production associated with exposure to general and local vibration and who gave voluntary consent to the study. The average age of the examined cases is 45.57±2.28 years. Markers of bone formation and bone resorption in body fluids were analyzed. The statistical data were expressed as an average value ± standard deviation. The differences were checked using the T-test. The values of p <0.05 were considered statistically significant. Results. The T-score in patients of group 1 ranged from -1 SD to -2.5 SD (-1.41±0.07*), which corresponded to osteopenia. Elevated levels of CRP (4.24±0.20 mmol/L), ESR (8.91±0.45 mm/h) and leukocytes (12.91±0.70×109 g/L) were revealed among patients of group 1. Changes in the state of calcium-phosphorus metabolism among patients of the 1st group were noted. The formation of osteopenic syndrome was accompanied by an imbalance between the processes of resorption and bone formation in group 1 patients (p<0.05). Limitations. The process under study was osteopenic syndrome, 310 workers - a quantitative parameter, mining production - a qualitative indicator. Conclusion. According to the results of laboratory and instrumental methods of research, osteopenic syndrome was revealed in workers in vibrio-hazardous occupations. Its early diagnosis, determination of a complex of specific treatment and rehabilitation techniques will prevent the progression of the pathological process and maintain professional orientation.

Improved biological compatibility of carbon materials via aqua regia and CaCl2 treatments

In order to improve the bioactivity of three single-phase carbon materials (resin, pyrocarbon and graphite), chemical modification with aqua regia and CaCl2 solution was used to modify their original surfaces. The bioactivity of materials before and after modification was evaluated by in vitro apatite formation in simulated body fluids (SBF). The results showed that –COOH and Ca2+ were introduced on the sample surface by the chemical modification. The treated resin demonstrated the strongest ability to form a uniform and dense HAP coating after soaking in SBF for its largest specific surface area and the highest content of -COO-. The bone-like apatite coating demonstrated remarkably enhanced in vitro biocompatibility as indicated in the mouse fibroblast (L929) direct contact and ultrastructure observation. The transformation process of hydroxyapatite morphology in functional carbon materials, and the hydroxyapatite formation mechanism were systematically analyzed.