致密砂岩气是一类非常重要的非常规油气资源,但该类气藏岩石致密、孔喉细小、孔渗低、黏土矿物改造作用强、强亲水并且原始水饱和度低。钻井完井过程中该类气藏易受损害并难以解除,主要的储层损害类型包括固相堵塞、与液相侵入相关的敏感性损害和水锁损害、应力敏感性损害,其中液相损害的影响要大于固相侵入堵塞。采用常规的过平衡和欠平衡钻井技术由于严重的储层损害而普遍效率低,难以形成对该类气藏的有效勘探开发。理论和现场试验均表明,气体钻井技术是一种高效开发致密砂岩气藏的钻井技术,它不仅从根本上避免了钻井液钻井中由固、液相侵入引起的储层损害,有效保护了储层;还极大地提高了钻速,减少了钻井事故,缩短了建井周期。 Tight sandstone gas is a very important unconventional oil and gas resource. However, the gas reservoirs in this type of gas pool are compact with small pore throats, low porosity and porosity, strong remodeling of clay minerals, strong hydrophilicity and low initial water saturation. Such reservoirs are vulnerable and difficult to be dislodged during drilling and completion. The main types of reservoir damage include solid-phase plugging, sensitive and water-lock damage associated with liquid intrusion, stress sensitivity damage, and liquid damage The impact is greater than the solid intrusion blockage. Conventional overbalanced and underbalanced drilling techniques are generally inefficient due to severe reservoir damage and are not effective for effective exploration and development of such reservoirs. Both theoretical and field tests show that gas drilling technology is a kind of drilling technology that can efficiently develop tight sandstone gas reservoirs. It not only fundamentally avoids reservoir damage caused by solid and liquid intrusion during drilling fluid drilling, but also effectively protects reservoir Layer; also greatly increased the rate of drilling, reducing drilling accidents, shortening the well construction cycle.