Applicability Of Dissolved Fracturing Fluid In The Qinshui Basin CBM Wells

CBM is the rise in recent years, high-quality clean energy, with a high calorificvalue, combustion does not produce emissions, versatile, high economic advantages,much worldwide attention. China’s coalbed methane reserves, ranking third in theworld. However, China’s coalbed methane development of mining technology late,the technical level in China is relatively backward compared with the developedcountries in Europe and the United States. The coal seam is low voltage, lowpermeability reservoir heterogeneity and anisotropy. On the other hand, themechanical characteristics of the coal is the Young’s modulus, Poisson’s ratio, andeasily broken, the mechanical strength is weak, easily broken, shear stress, plasticdenaturation. Coalbed methane adsorption exist in the surface of the coal and rockparticles, usually require the coal seam fracturing treatment to coalbed methane;conventional hydraulic fracturing of coal reservoir damage, the fracturing effect is notideal. Qinshui Basin block Shizhuang South as the research object to study thegeological features of the area lump coal rock reservoir fracturing fluid, and dissolvedfocus on analysis of the applicability of the block, and combined with field Theconstruction of the effect of the fracturing effect analysis.Qinshui Basin Shizhuang South block in accordance with the relevant dataanalysis studies have shown that the stable development of the main coal seam of theblock15coal seam Lower Permian Shanxi Formation coal seams and CarboniferousTaiyuan Formation and belong to the low-voltage low permeability reservoirs, gascontent is generally between13to20m3/t (raw coal); gas saturation in57.62%, aredue to saturation, the difficulty of exploitation.Shizhuang South Block CBM mining, this paper proposes the use of dissolvedfracturing fluid to the coal seam fracturing treatment. Dissolved fracturing fluidsystem performance evaluation: dissolved fracturing fluid in the coal seam has a goodanti-swelling effect; initial fluid loss, fluid loss coefficient, the system no residue, hasa good flowback performance; dissolved fracturing fluid rheology test showed that dissolved the fracturing fluid has a strong shear resistance, good carrying capacity;damage to the coal and rock experiments show that dissolved fracturing fluiddisplacement process, dissolved pulverized coal and minerals in coal and rock, hasmade sewing the seam, the ability to pass seam, making coal and rock reservoirpermeability can be improved.Dissolution feasibility of coal and rock dissolved fracturing fluid analysis, themolecular structure of coal and rock condensed aromatic ring and a separate smallmolecules present in the coal molecules gap constitutes a, dissolved only need to meetthe solvent interaction the resulting energy is greater than the destruction of solvent-solvent interaction energy loss, can have a higher solubility. Surface by means ofmodern experimental analysis of coal and rock with soluble.Combined with the dissolution of the fracturing fluid Shizhuang South BlockCBM well site construction effect, dissolved fracturing fluid in the applicability of theblock. Compared to the activity of water the construction effect dissolved fracturingfluid fracturing effect is more obvious, sand-carrying ability, the ability to build seamfracturing fluid efficiency advantages, dissolved fracturing fluid application prospectson the block broad.