Seek What You Need

In Motive Disposition Theory, the affiliation motive describes our need to form mutually satisfying bonds, whereas the power motive is the wish to influence others. To understand how these social motives shape play experience, we explore their relationship to Self-Determination Theory and Flow Theory in League of Legends. We find that: higher intimacy motivation is associated with greater relatedness satisfaction, autonomy satisfaction, enjoyment, and the flow dimension of absorption; higher prosocial motivation with more effort invested and the flow dimension fluency of performance; and higher dominance motivation with lower relatedness satisfaction but higher competence satisfaction and increased flow in both dimensions. We demonstrate that in addition to being driven to satisfy universal needs, players also possess individualized needs that explain our underlying motives and ultimately shape our gaming preferences and experiences. Our results suggest that people do not merely gravitate towards need-supportive situations, but actively seek, change, and create situations based on their individualized motives.

Use of Hydraulic Test Data to Recognize Fracture Network Pattern of Rock Mass in Taiwan Mountainous Areas

Comprehensive information on fracture network properties around a borehole is indispensable for developing a hydrogeological site descriptive model. However, such information usually relies on various cross-hole field tests at a high cost. This study presents a cost-effective option regarding the identification of fracture network density around a borehole. Based on packer-test and drilling-core data from 104 boreholes in Taiwan mountainous areas, Barker’s generalized transient radial flow model and the concept of fractal flow dimension were used to reanalyze the existing hydraulic test data for obtaining the n value related to the geometry of groundwater flow for each test section. The analyzed n value was utilized to explain the characteristics of the fracture network in the adjacent area of each packer inspection section. The interpretation results were verified, using five hydrogeological indicators, namely rock-quality designation, fracture aperture, fracture density, hydraulic conductivity, and fracture/matrix permeability ratio. All hydrogeological indices have high correlations with flow dimension n values. Based on the verification results from using these indices, the proposed method in exploring such information was proven to be feasible. Finally, three practical relations were established, to provide additional information for designing and planning groundwater-related engineering systems in Taiwan mountainous areas.

A Parametric Study of Reservoir Cooling for Enhanced Recovery by Carbon Dioxide Flooding

Summary Slimtube experiments and analytical calculations show that minimum miscibility pressure (MMP) can significantly decrease with a relatively modest reduction in temperature. Compositional simulation, however, is often made under isothermal conditions even though a prior waterflood may have reduced reservoir temperature in the swept zones of the reservoir. This study uses computer simulation to examine how cooling by a prior waterflood can affect recovery during a carbon dioxide (CO2) flood by lowering the MMP in the swept zones. The results show that for the cases considered, injection of cooler water can increase incremental oil recovery (IOR) significantly because of MMP reduction in the zones swept by the solvent. A parametric simulation study demonstrates how injection temperature, initial reservoir pressure, formation heterogeneity, formation thickness, heat transfer with the overburden/underburden formations, and water-alternating-gas (WAG) ratio may affect the IOR. The simulations are conducted by a long waterflood of up to 2.0 pore volumes injected before CO2 injection. The water during the secondary recovery is injected at several temperatures for selected 1D, 2D, and 3D flow models. CO2 solvent is then injected continuously, or in WAG mode, at the same waterflood-injection temperature. The increase in IORs (greater than what would have been obtained by a standard CO2 flood at original reservoir temperature) varied greatly depending on the flow dimension, initial reservoir pressure, level of heterogeneity, formation thickness, degree of energy gain from the surroundings, and injection temperature. Increases in recovery by CO2 flooding varied from a few percent to nearly 30% of original oil in place, with the highest recoveries occurring in 1D flow. For the same flow dimension, the largest increase in recoveries is achieved when the MMP is sufficiently reduced by temperature so that an otherwise immiscible or near-miscible flood becomes a multicontact miscible flood. The results demonstrate that including temperature variations in the simulations is important for floods that are nearly miscible because recoveries are most affected in that region. Further, including temperature variations could be very important to improve the quality of history matches used to understand the reservoir.