EVALUATION OF THE QUALITY STANDARDS OF THE WATER DISCHARGED INTO THE SEA AFTER WASHING THE EXHAUST GASES

The main objective of this paper is to propose technical solutions for monitoring and recording data for a gas washing system on board a ship and to maintain in standard parameters the quality of surface water following the discharge of gas washing water from installations from the ship.The specific objectives of achieving the general objective are: the methods for evaluating the laboratory samples from the washing water evacuation, modeling the dynamics of the washing water and modeling the dispersion of the scrubber washing water on board for a case study,evaluation of the quality standards of the water discharged into the sea after washing the gases, the elements of calculation, modeling and graphical representation are present

Ventilation strategies and postoperative pain in laparoscopic cholecystectomy: pulmonary recruitment maneuver versus extended hyperventilation: a prospective randomized study

Objectives: Acidic milieu created by carbon dioxide is associated with post laparoscopic surgical pain. Gas washing techniques were used to reduce such effects. This trial compared pulmonary recruitment maneuver (PRM) versus extended hyperventilation technique (EHV) regarding postoperative pain profile in laparoscopic cholecystectomy patients. Methods: In a prospective, randomized controlled study, 90 patients, underwent laparoscopic cholecystectomy were divided into two equal groups; (PRM group) and (EHV group). Collected data included heart rate (HR), mean arterial blood pressure (MAP), visual analog score (VAS), the incidence of shoulder and sub-diaphragmatic pain, postoperative nausea, and vomiting (PONV). Results: The overall incidence of shoulder and sub-diaphragmatic pain, late VAS score (at 12, 24 hours) were lower in the EHV group, while hemodynamics, early VAS scores, rescue analgesic consumption, and PONV were comparable in both groups. Conclusion: Gas washing techniques improved safety and efficacy in improving pain profile following laparoscopic surgery. EHV provides less pain and more patients comfort than PRM, especially at delayed times.

Origin of deep heavy oils in the northwestern Junggar Basin (NW China) and implications for gas migration

Whether the northwestern Junggar Basin (NW China) has natural gas potential is an urgent but unresolved question. In this study, we discuss the origin of deep heavy oils (>2900 m) and its implication for gas migration and accumulation, based on a comprehensive investigation into physicochemical and geological properties of hydrocarbons in the northern Zhongguai High. Our results indicate that multiple-episode migration of hydrocarbons created four genetic types of oils and three genetic types of hydrocarbon gases and induced widespread gas washing. Relatively low maturity and gas washing are both responsible for the formation of the deep heavy oils. In detail, the migrating late-stage humic-type gases washed the encountered early stage low-maturity oils. The oil reservoirs lost their light fraction and evolved into heavy oils, which are preserved in the deep layer to the present, while the light-end components continued to migrate upward and accumulated as mixed gas pools or vented out of the system. The spatial distributions pattern of source rocks, heavy oils, and mixed gas clearly indicates the migration pathways of humic-type gases, which otherwise are difficult to define in the study area. Because the gases finally migrate into fault belts, their poor preservation condition likely results in the rare discoveries of gas fields. The favorable exploration targets for gas in the area are expected to be fault traps in fault belts, stratigraphic traps along the pinch-out boundary of the Upper Wuerhe Formation, and, particularly, the deep traps in the Mahu Sag.

Fluid Phase Simulation and Evolution of a Condensate Gas Reservoir in the Tazhong Uplift, Tarim Basin

The fluid phase and the evolution of the condensate gas reservoir in the Lianglitage Formation (O3), Well ZG7-5, Tazhong Uplift, were studied by integrating the PVTsim and the PetroMod software. The fluid phase was successfully simulated, and the burial, temperature, pressure, and pressure coefficient histories were reconstructed. The evolution of the fluid phase and its properties (density, viscosity, and gas-oil ratio) under the ideal and gas washing conditions was also explored. The simulated pressure-temperature (P‐T) phase diagram confirms that the reservoir fluid is in the condensate gas phase at present, with an order of critical point-cricondenbar-cricondentherm (CP‐Pm‐Tm). The temperature and pressure show an overall increasing trend considering the entirety of geological evolution. Under ideal conditions, fluid transition from coexisting gas and liquid phases to a single condensate gas phase occurred during the Late Cretaceous (80 Ma, T=135.7°C, and P=58.19 MPa). The density and viscosity of the liquid phase decreased gradually while the density and viscosity of the gas phase and the solution gas-oil ratio increased during geological processes. With the consideration of gas washing, the critical phase transition time points for 100% and 50% gas washing fluid are 394 Ma, 383 Ma, 331 Ma, and 23 Ma, as well as 266 Ma and 23 Ma, respectively. The average liquid phase density, gas phase density, and liquid phase viscosity under 100% gas washing are larger than those under 50% gas washing before 23 Ma (Miocene), while the gas phase viscosity values are similar for both cases. This study visually suggests that the temperature and pressure histories, which are controlled by the burial history and heat flow evolution, and gas washing have significant impacts on the formation of the condensate gas reservoirs and evolution of the fluid phase and its features in the Tazhong Uplift.

Two-stage air stripping combined with hydrolysis acidification process for coal gasification wastewater pretreatment

Coal gasification wastewater is mainly from gas washing, condensation and purification processes in the gas furnace with high NH3-N (nitrogen in water in the form of free ammonia (NH3) and ammonium ion (NH4+)), TN (total nitrogen) and refractory organics content, which will inhibit the subsequent biological treatment. The ‘air stripping – hydrolysis acidification – air stripping’ process was proposed as the pretreatment for coal gasification wastewater to improve the biodegradability and nitrogen removal, which could reduce the subsequent biological treatment load. The first-stage air stripping process before hydrolysis acidification could achieve a significant removal of NH3-N (97.0%) and volatile phenol (70.0%), reducing the corresponding toxicity on hydrolysis acidification. The group with air stripping had more abundant microbial communities and a more effective organic degradation performance in hydrolysis acidification than that without air stripping. The second-stage air stripping removed NH3-N released from hydrolysis acidification, and significantly reduced the TN concentration in effluent. The whole process achieved a TN removal from 2,000 ± 100 mg/L to 160 ± 80 mg/L, and a total phenols removal from 700 ± 50 mg/L to 80 ±20 mg/L.