Well Test Analysis Of Low Permeability Reservoir In

With the improvement of growth in energy demand and oil exploration and development technology level, the proportion of low permeability reservoir development is increasing. As an important role of apprehending and evaluation of oil and gas reservoirs, well test can provide a scientific basis for the development of oil and gas fields in a reasonable way. Due to the non-Darcy flow characteristics, the conventional oil and gas reservoirs seepage flow model based on the previous homogeneous reservoir can not adapt to the needs of low permeability reservoirs. Therefore, according to the detailed investigation on the well test analysis of low permeability reservoirs, early well test, well test curve automatic matching, and other related documents, combined with geological characteristics and well testing cases of M2well area, well testing models of low permeability homogeneous reservoirs, low permeability2-zone composite reservoir and fracturing vertical wells in low permeability reservoir have been established from the basic principle of low permeability reservoir percolation theory in this paper. Then through the numerical inversion of the results of Laplace changes, new type curves and the sensitivity analysis of different parameters to the type curves have been developed by programming. The pressure and pressure derivative curves produce different degrees of upwarping, deviate from the homogeneous reservoir0.5line because of the impact of starting pressure gradient in low permeability reservoir. The greater of the starting pressure gradient, the greater degree of the curve upwarping. Meanwhile, the early well test studies of small-signal extraction technique and deconvolution method have been established due to the M2area well testing curve does not appear radial flow line segment, and well test analysis exsits multiple solutions. By overcoming the multiple solutions, the reservoir parameters which reflecting the actual geological conditions can be obtained from the contrast well test analysis of early well test and Field test wells. Finally, because the shortcomings of conventional typical curve graph fitting, such as the strong artificial influence factors, the multiple solutions, the low precision et., the automatic matching method have been researched. Thourgh the application of improved ant colony algorithm on the well test analysis of the M2well area, satisfactory results of the interpretation can be obtained. It can provide a scientific basis for the efficient development and production for the M2class area of low permeability reservoirs.