奥陶系灰岩地层放空段堵漏技术

Plugging Technology for Limestone Cave of Ordovician Strata

摘要:

奥陶系灰岩放空段漏失封堵一直是堵漏中的难题，针对漏失通道尺寸大、堵漏浆难以滞留的问题，利用带正电强滞留、强度高、微膨胀的化学固结堵漏浆可对此类漏失进行有效封堵。化学固结材料成分中含有正电荷，可与漏失通道壁面上的负电荷产生电性吸附，提高滞留能力；化学固结浆固化后形成的固结物强度48 h可达17 MPa以上，具有较高的强度；固结物具有微膨胀功能，膨胀能力可达3.33%，可完全填充并封堵漏失通道；稠化时间可根据井下施工情况进行调整，满足安全施工的要求。化学固结堵漏技术在托普187井奥陶系灰岩放空漏失层进行了应用，通过3次封堵，漏失速度由失返降至0.1～0.2 m3/min，满足了继续强钻的要求。化学固结堵漏技术是一种可有效封堵放空段漏失层的堵漏技术。

Abstract:

Leakage plugging in Ordovician limestone cave has been difficult, as for the large leakage channel dimension and the slurry retention difficulty, the plugging technology of chemical consolidation with positive charges has excellent properties such as good retention, high strength and micro expansion. The chemical consolidation plugging agent contains positive charges, which can produce electric adsorption with the negative charges on the surface of leakage channel to increase retention ability; the strength of cured consolidating material can reach up to 17MPa in 48h, and the consolidating material has micro expansive function, the expansive ability can reach 3.33%, the leakage channel can be completely filled and plugged. The thickening time can be adjusted according to the underground construction situation. The chemical consolidation plugging technology was applied in well TP187 in Ordovician limestone cave, where the leakage rate was reduced from total loss to 1～2m3/10min in 3 times of plugging, which met the requirements of continuous drilling. Chemical consolidation plugging technology is effective in cave section leakage.