自固结堵漏技术在冀东油田G21X3井的应用

G21X3井是高南斜坡部位高21断块构造较高部位的一口重点预探井，完钻井深为4392 m。钻至井深2670 m时出现放空，钻井液失返。在东营一段、二段共漏失4次，先后组织进行8次不同类型堵漏作业，累计漏失量为250 m3，未堵漏成功。根据G21X3井地层井漏情况，在分析常规堵漏技术缺点的基础上，提出一种新的自固结堵漏技术。对自固结堵漏材料形貌特征、不同温度下固结效果、堵漏承压效果进行了评价。自固结堵漏技术是通过在云母、纤维、核桃壳、石英砂等材料上涂覆一层树脂，将这些涂覆后的堵漏材料泵入到漏层后，在发生物理堆积的同时，在井底温度作用下树脂发生缩聚反应，堵漏材料相互固结，增加了堵漏层的强度和稳定性。自固结堵漏技术在G21X3井进行了现场应用，并堵漏成功。自固结堵漏剂沿用原来复合堵漏的施工工艺，操作简便，适用性广，具有广阔的应用前景。 

Application of a Self-Solidifying Lost Circulation Material in Well G21X3 in Jidong Oilfield

The Well G21X3 is a key exploratory well drilled at the upper part of the Gao-21 fault in Gaonan slope. The designed completion depth of this well is 4,392m. When drilled to 2,670 m, the bit drilled into caves and the mud lost return. In drilling the Dongying-1 member and Dongying-2 member, totally four times of mud losses occurred and eight times of mud loss control jobs were performed. Totally, 250 m3 of mud was lost into the formation. To deal with the mud losses in the future, a new technology was presented based on the analyses of the deficiencies of the mud loss control techniques previously used. The new technology involves the use of a self-solidifying lost circulation material (LCM). Laboratory evaluation of the self-solidifying LCM was performed on its morphological feature, solidifying state at different temperatures and the pressure bearing capacity of the formation plugged with the self-solidified LCM. The mechanism of the self-solidifying LCM is to coat LCMs such as mica, fiber, nutshell and silica with a layer of resin, and these LCMs are then pumped into the loss channel, depositing there. The resin on the surface of the LCMs then condenses at the temperature prevailing in the loss zone and solidifies into hard lumps, thereby increasing the strength and stability of the LCMs. This technology has been successfully used in controlling mud losses occurred in the Well G21X3. The procedure of using the selfsolidifying LCM is the same as that of the compound LCMs, and is easy to operate. This technology is widely applicable, and has broad prospects of application.