四川筠连沐爱核心区是中国南方第一个成功商业化开发多年的煤层气田，在南方煤层气开发中具有引领意义，然而其富集成因尚待进一步揭示。基于研究区大量的煤层气评价测试井、煤层气试井和煤层气开发井数据为基础，结合测试化验分析，参考并借鉴油气研究成果，结合地质背景，分析了其独特的煤层气富集成藏模式。研究认为：筠连沐爱核心区主力煤层平均含气量为15.58 m³/t，具有“中高灰分煤，高含气量和高饱和度”的特征，且发现原始气藏氦气异常，平均含量为0.074%，煤层气富集区主要位于铁厂沟向斜轴部沐爱断层东侧及区块西部和南部边缘，氦气异常区与煤层气富集区具有协同性。本区地下水矿化度高为其鲜明特色，TDS平均在10 638.3 mg/L，远高于国内外浅层煤层气产区的TDS值，且具有“高氯离子，高硫酸根离子”特征，这与其处于四川盆地边缘，构造活动较弱，地层水为泥岩压实排出水（古海洋水）混合大气降水密切相关。矿化度高的区域煤层含气量高，氦气异常，且具有超压现象，氦气异常推测主要来自深层离心流中水溶氦气的脱气作用。由此，提出了一种新的煤层气成藏模式，即构造−混合水动力封堵型富氦煤层气藏，构造主要体现2方面，一是封闭性好的逆断层为富氦煤层气富集提供了有益边界，二是构造形迹控藏，包括宽缓向斜轴部低部位控藏和构造高点高部位控藏。混合水动力则体现在独特的沉积盆地泥岩压实离心流和大气降水向心流的综合控制，促成了富氦煤层气藏的形成，由此导致，在原始气藏中地下水−煤层气a2氦气具有协同性，在后期长时间的排采过程中，这种动态协同性仍然一致。因此，煤层气藏中富氦可能是煤层气富集的重要指示性指标。

The Junlian Mu'ai core area of Sichuan province is the first successfully commercialized Coalbed Methane (CBM) field in southern China, which has leading significance in the development of CBM in southern China. However, its rich geological reason remains to be further revealed. Based on the data from a large number of CBM evaluation test wells, CBM test wells and CBM development wells in the study area, combined with testing and assaying analysis, referring to and borrowing from oil and gas research results, and combining with the geological background, the unique CBM enrichment and formation mode has been analyzed. The research shows that the average CBM of the main coal seams in Junlian Mu’ai core area is 15.58 m³/t, which is characterized by “medium high ash coal, high CBM content and high saturation”, and the helium is abnormal, with an average content of 0.074%. The CBM enrichment area is mainly located at the Mu’ai fault side of the syncline axis of Tiechanggou and the western and southern edges of the block. The helium anomaly area and the CBM enrichment area have synergy. The high salinity of groundwater in this area is its distinctive feature. The average TDS is 10 638.3 mg/L, which is far higher than the TDS value of domestic and foreign shallow CBM production areas. And it also has the characteristics of “high chloride ions, high sulfate ions”. This is closely related to its location at the edge of Sichuan Basin, weak tectonic activity, and the formation water is mudstone compaction drainage water mixed with atmospheric precipitation. The area with high salinity has high CBM content, helium anomaly, and overpressure phenomenon. It is speculated that the helium anomaly mainly comes from the degassing of water-soluble helium in deep centrifugal flow. Therefore, a new model of CBM reservoirs is proposed, that is, the structure-mixed hydrodynamic sealing helium-rich CBM accumulation model. The structure mainly reflects two aspects: one is that the reverse fault with good sealing provides a beneficial boundary for helium-rich CBM enrichment; the other is that the structural trace controls the reservoir, including the low part of the wide and gentle syncline axis and the high part of the structure. The mixed hydrodynamic force is reflected in the comprehensive control of mudstone compaction centrifugal flow and atmospheric precipitation centripetal flow in the unique sedimentary basin, which contributes to the formation of helium-rich CBM reservoirs. As a result, the water-CBM and helium gas in the original gas reservoir have synergism, and this dynamic synergism is still consistent in the later drainage and production process. Therefore, the enrichment of helium in CBM reservoirs may be an important indicator for the CBM enrichment.