MPC Corporation

Mud volcano (MV) is one of the most important passageways for deep seated volatile materials to migrate back to Earth's surface in sedimentary basins and subduction zones. Waters of MV fluid emitted from 18 mud pools in MV Luo-Shan (LS) in eastern Taiwan were sampled from the year 2002 to the year 2021. Major and trace components as well as H, triple O ( 18 O and 17 O) and triple Sr isotopes ( 87 Sr/ 86 Sr and 88 Sr) were measured. The results show that major components of water are Cl -, Na, and Ca. Compared with seawater, water of MV LS reveals similar chemical characteristics with low-temperature ridge-flank hydrothermal spring and marine pore water in reducing condition. Limited spatial and temporal variation of major components as well as H, triple O and 87 Sr/ 86 Sr indicates waters emitted by mud pools come from the same source regionally. Slightly radiogenic 87 Sr/ 86 Sr at southern mud pools and before the year 2003 denotes different fluid reservoir from northern ones. Small 87 Sr/ 86 Sr variation in waters of northern mud pools indicates near surface mixing from 2 fluid reservoirs. The correlation among all components reveals sediment component addition is the major factor and evaporation is the key factor for conservative elements. In summary, waters expelled by MV LS mud pools originate from the same regional source, and their trace element composition such as Mg, K, Sr as well as 87 Sr/ 86 Sr slightly varies, depending on the location of the reservoir they are hosted. A stable source with small vibration of fluid reservoir of MV LS is indicated during the 19-years investigation period.

In this work, we illustrate a facile and economical strategy for the bulk production of aqueous few layer graphene (FLG) dispersions via a simple grinding method.

SummaryDuring hydraulic-fracturing operations in low-permeability formations, spontaneous imbibition of fracturing fluid into the rock matrix is believed to have a significant impact on the retention of water-based fracturing fluids in the neighborhood of the induced fracture. This may affect the post-fracturing productivity of the well. However, there is lack of direct experimental and visual evidence of the extent of fluid retention, evolution of the resulting imbibing-fluid front, and how they relate to potential productivity hindrance. In this paper, laboratory experiments have been carefully designed to represent the vicinity of a hydraulic fracture. The evolution of fracturing fluid leakoff is monitored as a function of space and time by use of X-ray computed tomography (CT). The X-ray CT imaging technique allows us to map saturations at controlled time intervals to monitor the migration of fracturing fluid into the reservoir formation. It is generally expected for low-permeability formations (5 to 10 md) to show strong capillary forces because of their small characteristic pore radii, but this driving mechanism is in competition with the low permeability and spatial heterogeneities found in low-permeability sands. The relevance of capillarity as a driver of fluid migration and retention in a low-permeability sand sample is interpreted visually and quantified and compared with high-permeability Berea sandstone in our experiments. It is seen that although low-permeability sands are subject to strong capillary forces, the effect can be suppressed by the low permeability of the formation and the heterogeneous nature of the sample. Nevertheless, saturation values attained as a result of spontaneous imbibition are comparable with those obtained for high-permeability samples. Leakoff of fracturing fluids during the shut-in period of a well can result in delayed gas flowback and can hinder gas production. Results from this investigation are expected to provide fundamental insight regarding critical variables affecting the retention and migration of water-based fracturing fluids in the neighborhood of hydraulic fractures, and consequently affecting the post-fracturing productivity of the well.

Risk-based corrective action (RBCA) is a scientifically-accepted approach to remediate polluted sites. Under the RBCA approach, the risks to human health associated with polluted sites are assessed and appropriate remedial measures are taken to reduce risks. RBCA evaluations involve the use of risk models to assess health risks to different receptors. In Taiwan, the Soil and Groundwater Remediation Act was enforced in 2000. The government of Taiwan also use risk assessment protocols to obtain acceptable remediation goals for polluted sites with low risks. In this study, the application of risk assessment to derive remediation goals and develop remedial strategies at a fuel-oil spill site were performed. After the risk evaluation, the soil and groundwater remediation goals for total petroleum hydrocarbon (TPH), benzene, toluene, ethylbenzene, and xylenes (BTEX) were determined. The remediation levels meet with the requirements for minimum target risk levels (cancer risk = 1×10-6 and hazard quotient = 1). The developed risk-based cleanup goals are calculated based on actual land use and exposure pathways rather than on assumed maximum exposure. After the completion of RBCA process, the remediation cost can be significantly reduced. Based on the risk assessment results, source zone remediation, natural attenuation, and long term monitoring were recommended as the remediation strategies of the studied site to reduce risks to human health. Results from this study provide a streamlined process for future risk assessment work at petroleum-hydrocarbon polluted sites in Taiwan. RBCA is a sound and defensible basis for site closure, and it offers a more logical framework for making site closure decisions.

The AIM and EDA concepts are founded on the principles of inertial impaction of aerosol particles under laminar flow conditions. This chapter examines the current CI systems that are recognized by the pharmaceutical compendia, providing a summary of the key parameters that affect the size-resolving capability of each system. The potential for bias introduced through the assumption that individual stage collection efficiency curves are step functions at the calibration size is explored, with attention given to the effect of removing stages in order to achieve an AIM-based configuration. Non-sizing accessories, such as the induction port (IP) entry and preseparator (PS), are discussed and the chapter concludes with consideration of how add-on devices, such as spacers and VHCs that are commonly used in conjunction with MDIs, should be evaluated.

Fractures serve as primary conduits having a great impact on the migration of injected fluid into fractured permeable media. Appropriate transport properties such as relative permeability and capillary pressure are essential for successful simulation and prediction of multi-phase flow in such systems. However, the lack of a thorough understanding of the dynamics governing immiscible displacement in fractured media, limits our ability to properly represent their macroscopic transport properties. Previous experimental observations of imbibition front evolution in fractured rocks are examined in the present study using an automated history-matching approach to obtain representative relative permeability and capillary pressure curves. Predicted imbibition front evolution under different flow conditions resulted in an excellent agreement with experimental observations. Sensitivity analyses, in combination with direct experimental observation, allowed exploring the competing effects of relative permeability and capillary pressure on the development of saturation distribution and imbibing front evolution in fractured porous media. Results show that residual saturations are most sensitive to matrix relative permeability to oil, while the ratio of oil and water relative permeability, rock heterogeneity, boundary condition, and matrix–fracture capillary pressure contrast, affect displacement shape, speed, and geometry of the imbibing front.