Zhu Jinzhi, Lou Erbiao, Zhang Shaojun, Lu Haiying, Wang Ziwu
PetroChina Tarim Oilfiled Company, Korla 841000, China.
Gels. 2023 Oct 30;9(11):862. doi: 10.3390/gels9110862.
Aiming at the complex strata, lost circulation often occurs. and lost circulation control becomes a difficult issue. A drilling fluid loss accident delays the drilling progress and even causes major economic losses. If we take a self-made sodium polyacrylate grafting and modify a starch water absorbent resin, using an amphiphilic compatibilizer as raw material through mechanical blending and chemical compatibilization, we can synthesize a resin-rubber blend swelling lost circulation material. This material presents a good resistance to anti-high-temperature performance, but the quality declines while the temperature is higher than 363 °C, and with the increasing temperature, the water-swelling expansion ratio becomes higher. The range of the water-swelling expansion ratio is 8 to 25 times and the water swelling rate becomes larger along with the reduced diameter of the lost circulation materials and decreases with the increasing salinity. The resin-rubber blend swelling lost circulation material after water swelling has excellent toughness and high elastic deformation capacity, thus, forming a 7 Mpa to 2 mm fracture via expansion, extrusion, deformation, and filling, which presents a good performance for fracture plugging and realizes the purpose of lost circulation control.
针对复杂地层，常常会发生漏失，漏失控制成为一个难题。钻井液漏失事故会延误钻井进度，甚至造成重大经济损失。若以自制的聚丙烯酸钠接枝改性淀粉吸水树脂为原料，采用两亲性相容剂，通过机械共混和化学增容合成一种树脂 - 橡胶共混型膨胀堵漏材料。该材料具有良好的抗高温性能，但温度高于363℃时性能下降，且随着温度升高，水溶胀倍率增大。水溶胀倍率范围为8至25倍，水溶胀速率随堵漏材料粒径减小而增大，随矿化度升高而减小。树脂 - 橡胶共混型膨胀堵漏材料水溶胀后具有优异的韧性和高弹性变形能力，通过膨胀、挤压、变形和填充形成7兆帕至2毫米的裂缝，堵漏性能良好，实现了控制漏失的目的。
