阅读说明：本技术 致密砂岩储层孔隙可动性分类及评价方法 (Compact sandstone reservoir pore mobility classification and evaluation method ) 是由 刘景东 刘桃 蒋有录 徐加乐 于 2019-10-15 设计创作，主要内容包括：本发明涉及一种致密砂岩储层孔隙可动性分类及评价方法,其具体步骤为：S1、制备样品,对样品进行核磁共振和高压压汞测试；S2、依据进汞饱和度S<Sub>Hg</Sub>和进汞压力P<Sub>c</Sub>绘制压汞曲线、Pittman曲线以及分形曲线,依据压汞曲线的“平台段”与“递增段”的界限、Pittman曲线的顶点以及分形曲线的转折点,确定粒间孔隙与粒内孔隙的界限,根据界限划分出粒间孔隙和粒内孔隙；S3、依据饱和水核磁曲线与束缚水核磁曲线的关系,结合粒间孔隙与粒内孔隙的界限,将粒间孔隙划分为可动大孔隙和孤立大孔隙,将粒内孔隙划分为可动微孔隙和不可动微孔隙；S4、计算不同类型孔隙含量。本发明能够实现对致密砂岩储层不同类型孔隙可动性的评价,使储层孔隙的可动性评价更符合实际地质情况,评价结果更为准确。(The invention relates to a compact sandstone reservoir pore mobility classification and evaluation method, which comprises the following specific steps: s1, preparing a sample, and performing nuclear magnetic resonance and high-pressure mercury injection test on the sample; s2 according to mercury inlet saturation S Hg And mercury feed pressure P c Drawing a mercury intrusion curve, a Pittman curve and a fractal curve, determining the boundary of inter-granular pores and intra-granular pores according to the boundary of a 'platform section' and an 'increasing section' of the mercury intrusion curve, the vertex of the Pittman curve and the turning point of the fractal curve, and dividing the inter-granular pores and the intra-granular pores according to the boundary; s3, dividing the inter-granular pores into the regions with the boundary between the inter-granular pores and the intra-granular pores according to the relation between the saturated water nuclear magnetic curve and the bound water nuclear magnetic curveA movable macropore and an isolated macropore, which divide the intra-granular pores into movable micropores and immovable micropores; and S4, calculating the content of different types of pores. The method can realize the evaluation of the mobility of different types of pores of the compact sandstone reservoir, so that the mobility evaluation of the pores of the reservoir is more consistent with the actual geological condition, and the evaluation result is more accurate.)

1. A compact sandstone reservoir pore mobility classification and evaluation method is characterized by comprising the following specific steps:

s1, preparing a sample, and performing nuclear magnetic resonance and high-pressure mercury injection test on the sample

Preparing a sample, and sequentially carrying out nuclear magnetic resonance test and high-pressure mercury pressing test on the sample to obtain a saturated water nuclear magnetic curve, a bound water nuclear magnetic curve and mercury inlet saturation S_HgAnd mercury feed pressure P_c；

S2, dividing inter-granular pores and intra-granular pores

According to mercury saturation S_HgAnd mercury feed pressure P_cDrawing a mercury intrusion curve, a Pittman curve and a fractal curve, determining the boundary of inter-granular pores and intra-granular pores according to the boundary of a 'platform section' and an 'increasing section' of the mercury intrusion curve, the vertex of the Pittman curve and the turning point of the fractal curve, and dividing the inter-granular pores and the intra-granular pores according to the boundary;

s3, dividing the movable pore and the immovable pore

According to the relation between the saturated water nuclear magnetic curve and the bound water nuclear magnetic curve, combining the limits of inter-granular pores and intra-granular pores, dividing the inter-granular pores into movable macropores and isolated macropores, and dividing the intra-granular pores into movable micropores and unmovable micropores;

s4, calculating the content of different types of pores

Dividing the saturated water nuclear magnetic curve, the bound water nuclear magnetic curve and the abscissa enveloping surface into 4 regions of a movable macropore region, an isolated macropore region, a movable micropore region and an unmovable micropore region, and respectively calculating the area ratio of the four regions to the total enveloping surface to obtain the proportion of the movable macropore, the isolated macropore, the movable micropore and the unmovable micropore to the total pore.

2. The tight sandstone reservoir pore mobility classification and evaluation method of claim 1, wherein in step S1, the concrete steps of preparing the sample are as follows: selecting typical sandstone of a compact sandstone reservoir in a research area, preparing a standard core plunger sample with the length of 3cm and the diameter of 2.5cm, and performing salt washing, oil washing and drying treatment to obtain the sample.

3. The method for classifying and evaluating the mobility of tight sandstone reservoir pores according to claim 1 or 2, wherein in step S1, the specific steps of performing the nmr test are as follows:

putting the sample into a high-pressure saturated water instrument, vacuumizing, injecting a pre-prepared stratum aqueous solution until the sample is completely saturated, and performing saturated water nuclear magnetism measurement to obtain a saturated water nuclear magnetism curve;

and centrifuging the sample to a bound water state and carrying out bound water nuclear magnetism determination to obtain a bound water nuclear magnetism curve.

4. The method for classifying and evaluating the pore mobility of tight sandstone reservoir of claim 3, wherein in step S1, before the high-pressure mercury intrusion test is performed, and after the nuclear magnetic resonance test is completed, the sample is subjected to salt washing and drying treatment.

5. The tight sandstone reservoir pore mobility classification and evaluation method of claim 1, wherein in step S2, the mercury saturation S is determined according to the mercury injection_HgAnd mercury feed pressure P_cThe method for drawing the mercury intrusion curve, the Pittman curve and the fractal curve comprises the following steps: at mercury ingress saturation S_HgAs abscissa, with mercury feed pressure P_cDrawing mercury intrusion curve for ordinate to determine mercury intrusion saturation S_HgAs abscissa, in mercury saturation S_HgWith pressure P of mercury entering_cRatio of (A to (B)Value S_Hg/P_cPlotting a Pittman curve for the ordinate to the mercury inlet pressure P_cLog of lg (P)_c) As abscissa, in mercury saturation S_HgLog lg (S) of_Hg) Fractal curves were plotted for the ordinate.

6. The tight sandstone reservoir pore mobility classification and evaluation method of claim 5, wherein the vertex of the Pittman curve is S_Hg/P_cThe point at which the maximum is reached is defined as the Swanson parameter, the pore size for which Swanson parameter corresponds is called Rapex, and the Swanson parameter is the point of demarcation between the intergranular and intragranular pores.