The Exploitation Strategy Of Water-rich Region On Compact Sandstone Gas Reservoir

Zizhou gas field is located in the northeast of the Ordos Basin, structure belongsto the tectonic units of the YiShan slope, and constructed flat. However, there isunclear gas-water contact in HE8and SHAN2gas reservoir of the Ordos Basin, andthe formation water is neither the typical edge water nor typical bottom water. Now inHE8and SHAN2formation has been found more gas reservoirs, which SHAN2gasreservoir is the most favorable development in Neopaleozoic. And SHAN23is themain producing layer of the SHAN2gas reservoir. Therefore, the exploitationstrategy for water-rich region of SHAN2gas reservoir has the great significance forthe gas field development of the next step. In this paper with SHAN2gas reservoirsas the object of study, analysis of water chemistry data of the gas well produced water,research the production dynamic characteristics of the gas-water well and the type ofwater, discuss the water pumping gas production technology which suitably forresearch work area, combined with numerical simulation techniques, and ultimatelyraised the rational exploitation strategy for water-rich region of gas reservoir.According to the results of well logging interpretation, gas testing data, theresults of water chemistry, the producting water of production well of the researcharea is classified into three types: formation water, condensate water, residualfracturing fluid. In this study, in accordance with the occurrence of the formationwater in the ground state, formation water will become three subcategories: local edgeand bottom water, lenticle water, lagging water. According to the water chemical dataof formation water in research area, analysis the water chemical characteristicscoefficient of producing water on different regional, and through the comparisonfound that the formation water of each water-rich area has certain differencecharacteristics, and proves each water-rich area does not mutual connectivity.According to the changes of water-gas ratio, gas-water wells are divided into three types, namely: water-gas ratio decline, water-gas ratio steadiness, water-gas ratioincrease. Combined water chemical analysis data, combined with the water chemicalanalysis data, producing water types, summarizes the change rule of producing water.Using various productivity analysis method to solving gas well productivity ofSHAN2gas reservoir, to verify the single well open-flow capacity. Comprehensiveanalysis affecting factors of gas well productivity (water saturation, storagecoefficient, formation capacity, formation thickness), consider the master controlfactor of affecting gas well productivity was storage coefficient.Water pumping gas production is common gas extraction process during the gasfield production, and there are many methods of gas drainage. This paper focuses ondiscuss the advantages and disadvantages of four kinds of drainage gas productiontechnology from coiled tubing drainage, gas lift drainage, electric pump drainage,foam drainage. Consider the cost, operation, management and the actual formationcondition of research area, ultimately determine using of coiled tubing drainage gasrecovery process. According to the gas well production performance, for less waterproduction wells, to calculate the critical output of liquid carrying, and analysis theliquid carrying capacity of gas well under its own energy in the present circumstances.When there existing the bottom water, get the critical production to avoid waterconing by calculation. While production wells on the edge of the water-rich area,using numerical simulation technology to build the model of edge water, get rationalspacing between wells and production rate gas. If the water energy of water-rich areais too small, using “based on discharge water“as development measures. At the earlystage of production, use the pre-existing conditions to production by its own energy.After its formation energy exhausted, can use coiled tubing drainage or foam drainagemeasures to production. If the water energy of water-rich area is too big, it can dropthe internel press and control the external production rate.Through the geologic research and the dynamic property analysis of Zizhou gasfield, the author has obtained a clear understanding about the water production type,production performance and the exploitation strategy of the water-rich area. Thisresearch provides reliable foundation for the future exploitation and programregulation of the gas reservoir, and meanwhile provides the research idea for the sametype of gas reservoir’s exploitation.