Study and Application of Combination Cementing Technology of Gypsum Salt Layer in Kuqa Piedmont Structure, Tarim Basin

Kuqa piedmont is the main battlefield of natural gas production in the oil field and the source of west-east gas transmission. The wellbore quality is related to the safety of well construction and production. However, the well cementation quality of the piedmont salt layer is affected by the narrow density window, low casing center degree, and narrow annular gap. Moreover, the qualified rate of well cementation has only been around 50% for many years, which seriously threatens the integrity and safety of the wellbore. Although wildcatters have conducted a series of technical research and practical exploration for many years, the actual application effect is not good. The problem of the inferior well cementation qualitied ratio in the gypsum salt layer is still prominent. Because of the above objective problems and technical limitations, this paper deeply analyzes the influencing factors of the well cementation, which has the qualitied ratio of the gypsum salt layer in the piedmont structure. Based on the three basic points of (1) casing running, (2) column centering, and (3) cementation leakage prevention, this paper studies and applies the combination cementation technology of reaming technology, coupled casing, and fine pressure control, aiming to provide new guidance for the development of the cementation operation of gypsum salt layer, the results of quality improvement and efficiency are remarkable.