Prediction Flooding of Well Stock on the Large Gas Fields with Stratified Heterogeneity

Ponomarev, Aleksandr (Ufa State Petroleum Technological University) | Shayakhmetov, Airat (Ufa State Petroleum Technological University)


Practically all large gas deposits of Russia are developed on the elastic water-pressure mode. At initial stages of their development owing to a lack of data on a productive layers structure there are considerable uncertainty at creation of 3D geological and hydrodynamic models of a deposit. At the same time relevant regulations on drawing up design and technological documentation provide calculation of indicators for the entire period of development of an object before the fullest extraction of reserves of gas. As practice shows, 3D digital models of large gas deposits are exposed to periodic specification on a measure of replenishment of geological field information what leads to essential change of initial estimates of technological indicators and efficiency of investments. In these conditions gain development and application of proxy models of the bedded systems using the steadiest characteristics of heterogeneity of collectors and geometry of deposits. It is also relevant to use such models for the developed fields at expert assessment of results of 3D hydrodynamic modeling. Simultaneous using of several approaches and tools when calculating process of development will allow to reduce risks and to narrow area of change of probable values of technological and technical and economic indicators of gas production.

Considered methodology assumes creation of zone and layered and non-uniform model of a gas deposit with use of the probabilistic determined approach to distribution of filtrational parameters on deposit model volume. Intake of reservoir water in a deposit happens to plantar water both on bedding, and in the vertical direction taking into account anisotropy of layers. When forecasting flood of a well stock mechanisms of accounting of a variability of wells on gas and water due to selective flood of productive thickness on interlayer, distributions of reservoir pressure in a zone of placement of wells and the differentiated opening of the allocated interlayer of productive thickness in wells are put. Groups of wells on a state are allocated for each timepoint: not flooded, flooded – capable to take out the water arriving from layer and waters, flooded – incapable of full and continuous carrying out. The moment of a spontaneous stop of the flooded wells is defined on the basis of hydrodynamic calculations of a gas-liquid stream in lift columns of wells.

The algorithm is developed and the computer program of calculation of selective flood of productive thickness of a gas deposit and fund of production wells is created. The technique is approved on Cenomanian deposits of the Yamburg, Urengoy and Medveghiy fields. The received results on indicators of stock of flood well satisfactory are coordinated with historical data.