SN油田随钻堵漏钻井液技术的研究与应用

Design and Application of Drilling Fluid for Lost Circulation Control While Drilling at SN Oil Field in Jiangsu

江苏SN油田S7、S19、S20、S30等区块钻井中常发生钻井液漏失，主要发生在戴南组、阜宁组辉绿岩层成套、裂缝发育的地层。在专门研制的DL-2堵漏实验仪上，使用分别以粒径1～2cm和2～3cm碎石充填的大尺寸（φ10cm×60cm）人造岩心，通过测定承压强度、憋压能力、侵入深度、漏失量、返排压力，考察了加入橡胶粒子RP、商品单向封堵剂DF-2、棉籽壳粉、杏仁壳粉的10％膨润土浆的堵漏效果，确定了此堵漏浆的工作配方。设计了应对辉绿岩段裂缝漏失的随钻堵漏施工工艺，并成功用于5口井的钻进，介绍了其中的S20—54井1640-1840m长辉绿岩裂缝段随钻堵漏工艺措施。还介绍了S19—41井钻井中，在常发生砂砾岩渗漏和玄武岩裂缝性漏失的700～1900m井段采取的分段随钻堵漏工艺措施。图2表2参2。

At blocks S7, S19, S20, and 5330 of SN oil field, Jiangsu, drilling complications and troubles often happened because mainly of stratified fractured diabase in Dainan and Funing Formations. On a specially designed laboratory installation for lost circulation control, DL-2, with physical models of large size, φ10×60（cm）, rubble packs of granule size 1--2 and 2--3 em, respectively, the plugging/sealing capability of 10% bentonile mud with rubber particles RP, commercial unidirectional sealing agent DF-2, powdered cottonseed shell and almond shell added is investigated through determining bearing capaeity, pressure maintenance, incursion depth, leakoff, and baekflow pressure and working recepts of the lost circulation fluid are formulated. A technology for lost circulation control while drilling in fractured diabase zones is designed and applied successfully in 5 well drilling jobs with one well case of drilling in fraetured diabase section 1640--1840 m long in well S20-54 examplified. Measures are stated for lost circulation control while drilling in long section 700--1900 m in well S19-41, where fluid losses were often observed by the way of percolation in glutenite zones and of leakage into basalt fractures.