In addition, we can see from Table 3, the soil respiration intensities from plots compacted by machineries are inferior to natural soil except some special cases, indicating that the soil compactions caused by mechanical compaction have a bad effect on soil respiration, so the compaction times should be paid attention to when using machinery.
In this paper the mechanical properties of earthen bricks produced by manual compaction have been investigated by a combined experimental and theoretical approach.
Chlorite coating pre-dates quartz overgrowth, Type II calcite, and pore-filling chlorite (Fig. 4a, d) and is absent along the intergranular straight contacts (Fig. 5), showing that sandstones have undergone mechanical compaction to a lesser extent.
Previous studies have suggested that mechanical compaction is influenced by a combination of various factors such as burial depth, sediment composition, particle size, sorting, abnormally high pressure, and burial time (Liu et al. 2007; Aplin et al. 2006).
During sandstone mechanical compaction, the evolution of porosity and permeability has a segmentation characteristic with the increasing overburden pressure and depth, and the evolution curves can be divided into two sections, i.e., a rapid compaction stage with a steep slope at the earlier stage and a slow compaction stage at the later stage.
Primary pores have been lost mainly by mechanical compaction.
However, current studies about various factors influencing compaction mainly focus on simple and qualitative description, and little work has been done on quantitative analysis based on simulation experiments, leading to the vague understanding of the evolution of physical properties and influencing mechanisms of various factors during mechanical compaction processes.
The main diagenetic types include mechanical compaction, cementation by carbonates, quartz and clay minerals, and dissolution which have directly influenced the reservoir quality.
The analysis shows that the evolution of porosity and permeability has a segmentation characteristic with the increasing overburden pressure and depth during mechanical compaction, and the evolution trend line can be divided into two stages.
Mechanical compaction was inhibited by the precipitation of pore-lining dolomite formed during early stage, and oil emplacement has further led to the preservation of good reservoir quality.
