How to say complete half of book, work

Dear all,

I just don't know exactly how to say in English "I have competed reading this much of the novel/I have completed this much of work. Regarding this I would like to know whether the following sentences are correct. If wrong, please correct them.

1) I have completed reading half portion of this book.

2) I have completed/read half of this book.

3) I have completed a quarter of this book.

4) I I have read three quarter of this book.

Thank you.