CAJ | 학술논문

通过对苏里格气田西部盒8段地层水性质及地球化学特征研究，推断地层水的成因，寻找天然气富集区，揭示气田油、气、水分布规律。苏里格气田西部39口井的地层水具有如下地球化学特征：①地层水阴、阳离子含量（ r）高低差异悬殊，阴离子以Cl-占绝对优势，HCO3-和SO2-4含量很低，阳离子以Ca2＋占优势，K＋＋Na＋含量也较高，Mg2＋含量低；②地层水呈弱酸性，具中-高矿化度；③水型以氯化钙Ⅴ型水为主，局部有氯化钙Ⅳ型和Ⅲ型水；④地层水化学特征参数具有钠氯系数（rNa＋/rCl-）低、脱硫系数（2×100× rSO2-4/rCl-）高、变质系数[12（rCl--rNa＋）/rMg2＋]高和镁钙系数（rMg2＋/rCa2＋）低的特征。研究结果表明：苏里格气田西部盒8段地层水具有油气伴生水特点，属于天然气充注时留下的残余地层水，形成于封闭、还原的水文地球化学环境。地层水分布受砂体和成藏条件控制，可能有3种成因类型：孤立砂体封闭地层水、弱动力生烃气水驱替不完全的残留水及大砂体低部位滞水。
통과대소리격기전서부합8단지층수성질급지구화학특정연구，추단지층수적성인，심조천연기부집구，게시기전유、기、수분포규률。소리격기전서부39구정적지층수구유여하지구화학특정：①지층수음、양리자함량（ r）고저차이현수，음리자이Cl-점절대우세，HCO3-화SO2-4함량흔저，양리자이Ca2＋점우세，K＋＋Na＋함량야교고，Mg2＋함량저；②지층수정약산성，구중-고광화도；③수형이록화개Ⅴ형수위주，국부유록화개Ⅳ형화Ⅲ형수；④지층수화학특정삼수구유납록계수（rNa＋/rCl-）저、탈류계수（2×100× rSO2-4/rCl-）고、변질계수[12（rCl--rNa＋）/rMg2＋]고화미개계수（rMg2＋/rCa2＋）저적특정。연구결과표명：소리격기전서부합8단지층수구유유기반생수특점，속우천연기충주시류하적잔여지층수，형성우봉폐、환원적수문지구화학배경。지층수분포수사체화성장조건공제，가능유3충성인류형：고립사체봉폐지층수、약동력생경기수구체불완전적잔류수급대사체저부위체수。
Genesis of formation water of 8th Member of Xiashihezi Formation (H8) and their relationships with gas accu-mulation in western Sulige gas field of Ordos Basin in central China was studied by means of analysis of the geochemical behaviors of formation water samples from 39 gas wells .The distribution regularity of oil ,gas and water was investigated . There is an obvious difference in the concentration ( r) of anion and cation of formation water .Content of Cl -is very high and dominant among the anions of the water ,while that of HCO 3-and SO 2-4 are very low .Content of Ca 2+is the highest among the cations of formation water ,followed by K ++Na +,while the content of Mg 2+is low.The formation water show property of weak acidity with medium-high salinity .The calcium chloride Ⅴ-type water is predominant ,with the calcium chloride Ⅲ-type and Ⅳ-type water occurring locally .The chemical characteristic parameters of the formation water are characterized by low sodium-chloride ratio (rNa +/rCl-),high coefficient of desulfurization (2 ×100 ×rSO2-4 /rCl-),high metamorphic coefficient[ 12 (rCl--rNa +)/rMg2+]and low magnesium-chloride ratio ( rMg2+/rCa2+).The formation water of H8 in western Sulige gas field has the characteristics of gas-associated water .It could be residual formation water formed when gas was charged under a closed and reducing environment .The distribution of formation water is controlled by sand body and reservoir conditions .Three genetic types of formation water are identified , namely the closed formation water within isolated sand body ,the residual water with weak dynamic and incomplete gas-water displacement ,and the stagnant water at lower position of large sand body .